Witnesses for the Prosecution: Forensic Science During Agatha Christie’s Life


Agatha Christie (1890-1976): Polymath and Natural Scientist

Agatha Christie was born in September 1890 and lived through 1976, so her work was inspired by and utilized the concepts of forensic science that were established during this time period.  

Christie had no formal education during her upbringing but was a polymath and a natural scientist.  Her father taught her arithmetic, and she had an inherent understanding of quantity, scale, and proportion.  She also taught herself to read and read a range of books and newspapers throughout her life, including the Daily Mirror and the Telegraph.  Examples of forensic science in action from these newspapers are shown below to illustrate what Christie was exposed to.

Agatha Miller
Young Agatha Christie

Foundations of Forensic Science

The earliest written accounts of the use of forensic science were in 6th century China.  The term “forensics” comes from the Latin “forensis,” which means “of or before the forum.”  The primary definition of “forensic” is belonging to, used in, or suitable to courts of justice or to public discussion and debate.

Forensic science, the focus of this post, refers to the application of scientific principles and techniques to matters of criminal justice especially as relating to the collection, examination, and analysis of physical evidence.  According to the Canadian Society of Forensic Science, 

Forensic science is therefore the application of science, and the scientific method to the judicial system. The important word here is science. A forensic scientist will not only be analyzing and interpreting evidence but also challenged in court while providing expert witness testimony.”

Criminalistics refers to the specific scientific tests or techniques that are used in connection with the detection of crime.  Criminalistics is a subset of forensic science and started with the “scientific aids” movement in the UK.  An example of criminalistics would be the collection of fingerprints at the scene of a crime by a CSI technician, which are then examined by a forensic scientist with an expertise in fingerprinting.

Forensic Science and Agatha Christie at the Turn of the 20th Century

At the turn of the 20th century, around the time that Agatha Christie was born, the field of forensic science had evolved to suit the need to present evidence in a courtroom, which was (as it is now) primarily done through expert witnesses.  The earliest types of witnesses were medical experts, such as a doctor testifying as to the cause of death, but by the end of the 19th century, other scientific fields were beginning to be represented.

Below is an example from the Daily Telegraph from the Dreyfus trial in 1899 detailing the testimony of a handwriting expert.  This was Captain Alfred Dreyfus’s second trial for treason against France, and he was erroneously found guilty based on this expert handwriting analysis.  The case is an example of the theoretical nature of many areas of forensic science as well as the influence that the media has in portraying forensic science as a single source of truth.  The case was also an example of unchecked antisemitism, which was also present in Christie’s early works though lessened as she matured as an author and a human.  Dreyfus was subsequently pardoned and served in World War I.

Early forensic science celebrity Bernard Spilsbury

At this time, a few forensic science techniques were already widely accepted, most notably fingerprinting analysis. One of the first celebrities in forensic science in the UK was Bernard Spilsbury, a Home Office forensic scientist. His authoritative performances in the witness stand, for example at Crippen’s trial, were held as an example until the 1980s. But his celebrity status led the public to conclude that forensic science would provide absolute, unquestionable proof.

Spilsbury gave compelling evidence based on his microscopic examination of human remains recovered in Crippen’s home that a scar on a piece of skin identified the remains as those of Crippen’s wife, whom Dr. Crippen killed and then escaped with his mistress via ship to Canada.

The Crippen case was among the first true crime cases to receive full media coverage complete with descriptions of recent scientific advances such as the wireless telegraph.  Christie would have read about the case and its trial, and even used it as inspiration for the historical crime in the 1952 Poirot novel Mrs. McGinty’s Dead.

Also in the 1910’s, Christie began volunteering as a nurse and may have chosen nursing as a career, if she had not become a successful writer.  But many of the best scientists are inherently creative, and Christie had a keen interest in science throughout her life.  She also married science with her creative writing, for example with her poem “In a Dispensary.”

She transitioned from nursing to dispensing (also known as pharmacy) during World War I.  As part of her training, she learned chemistry and physics and kept notebooks listing various substances (their appearances and properties) in alphabetical order.

Christie volunteered as a nurse and dispenser during World War I
pharmacy, apothecary, dispensary
Worshipful Society of Apothecaries arms

In 1917, she passed 2 of the 3 parts of the Society of Apothecaries’ examination: chemistry and medica (composition of medicines).  She passed the practical portion on her second try.

Forensic science to address criminal poisoning cases developed early in natural history, as early as the mid-18th century.  In the mid-19th century, the Society of Apothecaries began to require their candidates attend lectures in medical jurisprudence.  At this stage, a doctor could harvest samples and organs for testing for the presence of poisons.

Christie’s knowledge from her dispensary training was most applicable to the study of poisons and toxicology.  More broadly, analytical chemistry was widely used for extracting metals, manufacturing synthetic dyes, and conducting quality control.  Analytical chemistry is an area of applied science that answers the questions about an unknown substance: what is there and how much exists.

The Institute of Chemistry was founded in 1877 in the UK, which formalized the field of analytical chemistry.  Additional formality to scientific careers was introduced in the early 20th century when the Department of Scientific and Industrial Research was established following World War I.

Daily Telegraph, Home Office
Excerpt from The Daily Telegraph, 23 Nov 1907

Christie used her knowledge of poisons to craft her first mystery novel, The Mysterious Affair at Styles, around 1916.  The book was not accepted for publication until several years later.  In the original draft of the novel, Hercule Poirot revealed the solution while serving as an expert witness in a murder trial, showing Christie’s knowledge of the forensic application of science.

The Relationship Between Mystery and Science

The transition from practical science into mystery writing was a natural one.  Essentially, science seeks to solve the mysteries of the universe.  Below on the left, this diagram shows the Scientific Method, which is the accepted stepwise process for conducting scientific endeavors.  After making observations, a scientist poses a question, which is answered by a hypothesis.  A hypothesis is a statement about the question that can be disproven or rejected.  The scientist then conducts experiments to test their hypothesis.  Once the experiments are complete, the scientist can reject or fail to reject their hypothesis, which leads to a conclusion to their question.  It may not be the answer, but it will provide information hopefully leading to the answer eventually.  It is a cyclical process that repeats ad infinitum.

Below on the right is a similar diagram showing the structure of a mystery story.  Of course, stories can vary in their presentation, but generally every mystery story has a central crime.  After the crime has occurred, a detective or other character collects clues to inform a theory of what has happened.  When the detective is confident in their theory, there is a confrontation with the criminal.  And like science, when the theory is tested, there is a conclusion to wrap up loose ends in the story and perhaps point to future stories.

detective, Sir Arthur Conan Doyle, Dr. Watson
Statue of Sherlock Holmes in Edinburgh

Christie was not the only author to transition from medical sciences into mystery fiction.  Sir Arthur Conan Doyle, the creator of Sherlock Holmes, was a physician, and Richard Austin Freeman, the creator of Dr. John Thorndyke, was educated in medicine.  But Christie distinguishes herself with her breadth of knowledge specifically regarding poisons

Forensic Science in the 1920s Through 1940s

The following decades were a period of growth by Christie the author and also in the field of forensic science in the UK.  Detectives with Scotland Yard had acknowledged that more knowledge and coordination were required to detect and apprehend criminals.  Below is an overview of the key forensic scientists and developments during this important time period, as Scotland Yard worked to incorporate forensic science to solve crimes. 

Hans Gross

Toxicology may be the first true forensic science, as the field developed in the 19th century specifically to be used to solve crimes. Somewhat later, crime scene analysis was developed by Hans Gross in his Handbook for Examining Magistrates.  His work was practical and addressed how to manage and preserve evidence from crime scenes. However, his work was marred by frequent references to the Romani as criminals.  When his handbook was first translated into English, it was done so in the British colony of India and transposed these racist beliefs onto the native tribes.  Eventually, newer editions of the work edited out these racist segments.  The importance of Gross’s work was its reliance on the materials at a crime scene that could be properly collected and serve as objective “witnesses” to a crime.  Crime scene analysis inspired by Gross’s work was adopted by Scotland Yard in the 1930s.

forensic science, crime scene analysis
forensic science, crime scene analysis
Clapham Crime, Hans Gross
Excerpt from The Ballymena Observer 18 Jan 1911

Cesare Lombroso

Cesare Lombroso measured and categorized an untold number of skulls in the hopes of quantifying criminality.  His work was translated into English in 1927 and introduced the notion of a “born criminal” that could be identified through physiognomy, and examples are shown below on the right.  It was never fully accepted in the UK, likely due to Lombroso’s reliance on theory rather than empirical science. 

forensic science

Alphonse Bertillon

Alphonse Bertillon created the Bertillon System, an anthropometric approach to measuring criminals and criminality, in 1879, but he also pioneered crime scene management and forensic photography.  Bertillon developed precise photography techniques of the face and profile of criminals, and his photographic techniques were applied to crime scenes as metric photography, which used physical measuring scales (such as rulers) to provide a permanent and accurate record of the crime scene including the location and size of objects.  Although fingerprinting ultimately proved superior to anthropometry in identifying criminals, the 2 techniques were used in concert for many years.  And of course, the mug shot technique developed by Bertillon is still in use.

Hand measurements in the Bertillon System

Juan Vucetich and Edward Henry

Fingerprinting for criminal identification was first used by Juan Vucetich in 1891 in Argentina.  Sir Edward Henry developed a fingerprinting system that was adopted by Scotland Yard in 1901 and was the basis for the US FBI criminal files created in 1924.  This adoption followed the recommendation by the Belper Committee of the Home Office to utilize fingerprinting alone for criminal identification.  Henry’s system includes subclassification of fingerprints with more than 1024 categories and subcategories.  Matches were made through manual examination of fingerprints with a magnifying glass and was therefore not useful if there was not a print in the catalogue to match to, and the system was also flawed by classification errors that could prevent the identification of a print.  In the 1960s, the first computer programs for fingerprint identification were based on the Henry system.

Edward Henry, Juan Vucetich
Juan Vucetich, Edward Henry

Edmond Locard

Edmond Locard was a French forensic scientist with an impressive laboratory in Lyon that was held as an aspirational example to forensic scientists in the UK.  Locard was known as the “French Sherlock Holmes” and proffered his exchange principle, which asserted that whenever there is contact between 2 items, there is an exchange of material; this is the basis of several forensic sciences such as fingerprints and fiber analysis.

forensic science

Sydney Smith

Sydney Smith served as a medicolegal expert for the Egyptian government prior to his appointment as a Professor of Forensic Medicine at the University of Edinburgh.  In 1924, he and his colleagues employed one of the earliest uses of ballistics to identify the gun used to assassinate Sir Lee Stack Pasha.  Similar to fingerprinting, the unique markings left on a bullet by a particular firearm were evaluated using a comparison microscope.

ballistics, forensic science, firearm

Alfred Lucas

Another early work in the field was Forensic Chemistry and Scientific Criminal Investigation by Alfred Lucas, first published in 1920.  Lucas was a British analytical chemist who had worked alongside Howard Carter in his Egyptian archaeological excavations.  The book was highly detailed and a basis of forensic science in the UK for several decades.  Lucas was also a correspondent of Nigel Morland, a crime fiction writer from the 1930s through the 1970s who would reference Lucas’s work throughout his fiction.

Nigel Morland, mystery, detective, crime, novel, pulp

Forensic Science and the Public

The media was a primary source of information about forensic technologies to both the public and criminals.  Alfred Lucas stated in Forensic Chemistry, “

...in fact the criminal is becoming so scientific, not only in his work, but also in the means he adopts to escape detection, that a scientist is needed to cope with him, that is to say, a scientist must be set to catch a scientist.”

As early as the Victorian era, there was considerable public interest in crime reporting.  At the turn of the century in the UK, the creation of tabloids capitalized on this appetite.  The reporting of the Crippen case offers the best study of the role of the press in disseminating knowledge of criminals and forensic science.  Most notably, the use of the wireless telegraph in apprehending Crippen was so widely described in the media that scholars have suggested 

the Crippen saga did more to accelerate the acceptance of wireless as a practical tool than anything the Marconi company had previously attempted.”

The Departmental Committee on Detective Work for England and Wales

In the 1930s, the Home Office commissioned the Departmental Committee on Detective Work for England and Wales “to inquire and report upon the organization and procedure of the police forces of England and Wales for the purpose of the detection of crime.”  Their report was submitted in 1938 and provided substantial evidence of the relationship between scientific training and analysis to the detection of crime.  This allowed for the establishment of additional laboratories with the purpose of solving crimes and essentially formalized the field of forensic science.

The Detective Committee report acknowledged that the majority of crimes in the 1930s were against property and not people.  Violent crimes (including sexual crimes) comprised about 2.5% of all crimes, violent crimes against property about 19.5%, nonviolent theft about 75%, and forgery about 1%.  Burglary and breaking and entering crimes had tripled since the beginning of World War I.  The report also acknowledged the ability of criminals to move location and evade detection, and so recommended the centralization of records as well as maintaining adequate local police forces.  The Detective Committee report estimated that 4% of crimes (>10,000) would require scientific analysis of evidence. 

Departmental Committee on Detective Work for England and Wales, forensic science
Excerpt from Linlithgowshire Gazette 30 Sep 1938
Excerpt from The Leeds Mercury 11 Apr 1935

Around the same time, in 1935, the Metropolitan Police opened its first forensic science laboratory in Hendon.  However, it initially struggled to work in concert with the police force, and little work was forwarded from Scotland Yard.  Coordination between police officers and forensic scientists was a continual challenge in the UK, as there were often class and educational divides between the 2 professions.

In 1946, a public education campaign released a film entitled Science Fights Crime to announce the resumption of detective training courses.  The video demonstrated the newest scientific methods in forgery, fingerprinting, burglary, self-defense, identification of suspects, ballistics, and infrared and ultraviolet photography.

Scientific Aids

Forensic science theories evolved along with technology.  In 1946, Sir John Maxwell, former Chief Constable of Manchester stated, 

...great progress has been made in the application of science as an aid to police work.  The introduction of the motor car...the use of wireless, the gradual development of police laboratories to help in crime investigation and the adoption of traffic signal lights are typical examples of the process of mechanization.”

This was the era of “scientific aids” in policing.  

Throughout this era, “scientific aids” were developed and promoted for use by police officers.  These are roughly equivalent to “criminalistics” and were to be used by police officers during their investigation of crimes to help allow for objectivity in the processing of crimes.  An instructional pamphlet published in 1936, Scientific Aids to Criminal Investigation, provided highly detailed descriptions for what to do at a crime scene.  There were several parts to this publication, a few of which are shown here.

The goal of scientific aids can be described by the following quote:

Scientific evidence, when properly interpreted, may thus provide, in certain classes of cases, a kind of proof which never lies and never alters its tale, and which, if placed before the Court by a competent witness, can be seen by Judge and jury for themselves.”

Forensic Science from the 1950s Onwards

As with many other fields, the development of forensic science paused during World War II, which stagnated scientific advancement for many years.  According to author Alison Adam, “the development of the forensic science profession was complex and piecemeal.”  The forensic science principles described in this presentation continued to be used throughout the remainder of Agatha Christie’s life, with few notable breakthroughs until the mid-1980s with the advent of DNA identification.

Dame Agatha Christie
Crime fiction evolved along with criminals and forensic science, and Alison Adam posits that both science and crime fiction strove to establish and maintain social and moral order at the turn of the 20th century.  Agatha Christie had a strong interest in criminology and forensic science throughout her career and stated in her autobiography, 
As a result of writing crime books one gets interested in the study of criminology.  I am particularly interested in reading books by those who have been in contact with criminals, especially those who have tried to benefit them or to find ways of what one would have called in the old days ‘reforming’ them–for which I imagine one uses far more grand terms nowadays!”

The Motley Few, Act II

**Contains major plot spoilers for The Coming of Mr. Quin and The Harlequin Tea Set and a minor plot spoiler for The Chocolate Box.**​


The Harlequinade Continues

It is fitting that Christie drew upon her favorite theatrical characters and grandmother’s figurines for her first Poirot short story.  In quick succession, she would publish her first Harley Quin story, The Coming of Mr. Quin (originally titled The Passing of Mr. Quin), in 1924.  The story begins at a New Year’s Eve party attended by Mr. Satterthwaite, who was:

Sixty-two--a little bent, dried-up man with a peering face oddly elflike, and an intense and inordinate interest in other people’s lives. All his life, so to speak, he had sat in the front row of the stalls watching various dramas of human nature unfold before him. His role had always been that of the onlooker. Only now, with old age holding him in its clutch, he found himself increasingly critical of the drama submitted to him. He demanded now something a little out of the common.
Mr. Satterthwaite from Agatha Christie's Death on the Cards by Modiphius, 2019

Satterthwaite is shortly to have his wish granted but first wonders about a couple who are attending the party, the Portals.  Alex Portal was of “usual good sound English stock,” but his wife, Eleanor, was Australian, and Satterthwaite particularly wondered why she dyed her light hair black.  He also noted that Alex seemed to be afraid of her, although it was obvious he loved her.

The other party attendees recount the story of Derek Capel, who formerly owned the house in which they are gathered.  Capel suddenly shot himself one day without an apparent reason.  While discussing the possibility of the house being haunted, three loud knocks are heard at the front door, ushering the arrival of Mr. Harley Quin:

Harley Quin, harlequin
Framed in the doorway stood a man’s figure, tall and slender. To Mr. Satterthwaite, watching, he appeared by some curious effect of the stained glass above the door, to be dressed in every colour of the rainbow. Then, as he stepped forward, he showed himself to be a thin dark man dressed in motoring clothes.

Quin says his car has broken down and joins the party guests; “as he sat, some effect of the firelight threw a bar of shadow across his face which gave almost the impression of a mask.”  Quin reveals that he had also met Derek Capel, and the group continue discussing his mysterious suicide.  Mr. Satterthwaite notices that Eleanor Portal is now eavesdropping on the conversation and concludes that the entire evening was orchestrated by Mr. Quin: “he was at the heart of the mystery pulling the strings, making the puppets work.”  

In due course, the full story of Capel’s death is recounted.  He had announced his engagement but could not identify to whom, which led his companions to think that the woman was either currently or very recently married.  Subsequently, the post arrived with newspapers and letters; Capel opened the newspaper, then went upstairs and shot himself.  This had occurred around the time that the Appleton case was in the newspapers, wherein an “old curmudgeon” (with a young and very fair wife) had been poisoned with arsenic or strychnine.  The wife was suspected, but there was not enough evidence to find her guilty at trial.

Mr. Quin guides the fellow men through the events.  Capel was in love with Mrs. Appleton and had added strychnine to her husband’s decanter of port about a week before the elderly man’s death.  Apparently an amateur toxicologist, Quin explains, “strychnine is not very soluble unless it is in the form of hydrochloride.  The greater part of it, put into the port, would be taken in the last glass, perhaps a week after he left.”  Reading in the newspaper that Appleton’s body was to be exhumed, Capel happens to see a police officer approaching the house from his window.  The newspaper is a few days late because of a sizeable snowstorm, and Capel assumes that the officer has arrived to arrest him for murder, and he shoots himself.  In actuality, the officer was returning a dog.

During his brief appearance at the party, Quin makes a special connection with Mr. Satterthwaite but departs once this solution is revealed.  His parting words are:

I must recommend the Harlequinade to your attention. It is dying out nowadays--but it repays attention, I assure you. Its symbolism is a little difficult to follow--but the immortals are always immortal, you know.

After Quin leaves, Mr. Satterthwaite observes a scene between Mr. and Mrs. Portal.  Alex asks her for forgiveness, now realizing the truth that she, as Mrs. Appleton, had not killed her husband.  Harley Quin’s intercession on that evening had saved their marriage and her life, as she admits that was going to kill herself that night: “that man–that chance passerby, saved me.”

One of the locations where Mr. Satterthwaite happens to meet Harley Quin is a restaurant called Arlecchino, after the original Italian for “harlequin.”

The other stories in the collection follow a similar presentation, with Mr. Satterthwaite finding himself in a situation involving a pair of lovers in trouble–from a haunted window, mysterious disappearances, hidden identities, and death.  The stories are not traditional Christie mysteries with an overt crime that requires solving from a brilliant detective but rather puzzling tales and circumstances that Harley Quin clarifies by aiding Mr. Satterthwaite in his ratiocination.  The review in the New York Times Book Review stated, “To call the tales in this collection detective stories would be misleading. For all of them deal with mystery and some of them with crime, they are, nevertheless, more like fairy tales.”

Although the collection of stories was well-reviewed, true to his nature, Harley Quin essentially disappeared from Christie’s subsequent literary output.  The character appeared in just two more stories, which were included in other collections: The Love Detectives and The Harlequin Tea SetNevertheless, Harley Quin is a unique and memorable character among all the characters created by Christie, and as he was beloved by her, these stories are highly recommended.

harlequin, Harley Quin

The Harlequin-inspired stories serve to almost bookend Agatha Christie’s career as the first Poirot (The Affair at the Victory Ball) and last ever (The Harlequin Tea Set) published short stories.  The Passing of Mr. Quinn was the first British film adaptation of one of Christie’s works.

The Harlequin Tea Set

The final story to feature Harley Quin, The Harlequin Tea Set, was also the last story of Christie’s to be published, in 1971.  In the story, Mr. Satterthwaite is waylaid by car troubles on his way to visit acquaintances in the country.  He passes the time at The Harlequin Cafe and reflects on his old friend, Harley Quin,

It was the word “harlequin” of course which had remained fixed in Mr. Satterthwaite’s mind, although just far enough back in his mind so that it had been difficult to recall it. The gay colours. The harlequin colours. And he had thought, wondered, had the absurd but exciting idea that in some way here was a call to him. To him specially. Here, perhaps, eating a meal or purchasing cups and saucers might be his own old friend, Mr. Harley Quin. How many years was it since he had last seen Mr. Quin? A large number of years. Was it the day he had seen Mr. Quin walking away from him down a country lane, Lovers’ Lane they had called it? He had always expected to see Mr. Quin again, once a year at least. Possibly twice a year. But no. That had not happened.
First US edition of The Harlequin Tea Set and Other Stories, G. P. Putnam's Sons, 1997

He admits to himself that he misses Mr. Quin and hopes that he shows up because when he did, it “was always an announcement that something was going to happen.”  A very short time later, Mr. Quin indeed arrives, the sunlight creating a “festoon of colours” from his plain black suit.  The two friends quickly become reacquainted, and Mr. Satterthwaite describes the family of Tom Addison, to whom he is on his way to visit.

The Harlequin Tea Set
The somewhat-complicated Addison family tree

It has been many years since Satterthwaite had last seen his friend, and Tom’s family has changed in the intervening time.  Tom and his late wife had two daughters: Lily, who was Satterthwaite’s goddaughter, and Maria, who died during childbirth.  Lily had also died in a car accident, leaving behind a son, Roland.  Roland’s father Simon remarried a woman named Beryl, who had a young son named Timothy.  Timothy and Roland are now young men in their early 20s and live with their family in a country home named Doverton Kingsbourne, where Satterthwaite is traveling.

Coincidentally, Beryl arrives at The Harlequin Cafe to buy some of the harlequin teacups to replace some that had broken earlier in the day.  Satterthwaite introduces himself and Harley Quin, who is also invited to join the family for tea, but he declines as he is “only passing by.”  Quin departs just as Satterthwaite’s car is returned, providing an enigmatic word that he thinks will be of use to Satterthwaite: Daltonism.

Upon arriving at Doverton Kingsbourne, Satterthwaite is reminded of the meaning behind the word when he sees his old friend Tom Addison wearing one red and one green slipper, but the reader is provided no additional detail as to the condition.  Satterthwaite sees Timothy and Roland for the first time in many years and remarks to himself that Timothy looks more like Lily than her biological son Roland.  Each attendee of the gathering has a different color tea cup; Timothy has a red cup, while Roland has a yellow cup.

While he watches the family and especially Beryl, Satterthwaite increasingly feels as if something important is going to happen, as portended by his meeting Harley Quin earlier that day.  Beryl brushes Timothy’s red cup off the table, shattering it, and she replaces it with a pale blue cup next to Tom’s pipe.  When Timothy’s cousin Inez accuses him of drinking from her cup, since it is now a blue cup instead of a red one, Timothy claims it must be his cup because it is right where he left it by the pipe.  He raises the cup to drink from it when suddenly the entire situation is made clear to Satterthwaite, who quickly tells Timothy not to drink from the cup.

An Ishihara color test plate. Readers with normal vision will see the number "74," readers with red-green colorblindess will read the number "21," and readers with total colorblindness may read no numbers.

Satterthwaite reveals that Daltonism refers to red-green colorblindness and that Timothy is afflicted by this condition, which therefore made him unable to discern between the two teacups.  Satterthwaite also realizes Timothy has inherited his colorblindness from his grandfather Tom (with his mismatched slippers).  He surmises that Beryl exchanged the identity of her son with Roland, the heir to Doverton Kingsbourne, when both boys were young in order to ensure her son would inherit Tom’s estate.  Threatened with confrontation, Beryl flees.

Mr. Satterthwaite receives a note from Harley Quin, congratulating him on his success in preventing a murder, but the two friends are never to meet again in the fictional works of Agatha Christie.

Daltonism

Daltonism is another term for protanopia, which is colorblindness resulting from insensitivity to red light, causing confusion of greens, reds, and yellows.  This pattern of colorblindness is caused by alterations in the proteins responsible for the discernment of light wavelengths due to gene mutations on the X chromosome.  Because women have two X chromosomes, they are typically only carriers of the condition, and it is present in male relatives with one X chromosome.  Women can be affected by colorblindness due to mutations in other genes not on the X chromosome, but this is very rare.  It is also possible that a woman may inherit mutated X chromosomes from both parents (an affected father and a carrier mother), but this is also rare.

The name Daltonism was applied to this condition because the chemist John Dalton provided the first written account of the affliction suffered by him and his brother in 1798.  The inheritance pattern of red-green colorblindness was identified in the late 1960s, and Agatha Christie incorporated this recent scientific discovery into one of her mysteries, as she had done throughout her career.  Christie also used colorblindness as a clue in a Hercule Poirot short story, The Chocolate Box, published in 1924.

X-linked recessive inheritance pattern

Harlequin Medical Disorders

While there are no known forensic science or criminology principles directly related to the Harlequinade, there are two rare but noteworthy skin disorders (and a third that is less uncommon) whose names are at least partially derived from the character of Harlequin.

Harlequin color change, or unilateral erythema

Harlequin color change, or unilateral erythema, is a harmless condition observed in approximately 10% of newborn babies and occurs when half of the baby’s skin exhibits a red color with no change in the other half.  The color change is well demarcated, as with a harlequin costume that is half red and half white.  Scientists speculate that the condition results from a temporary imbalance of the blood vessels in the skin that presents in newborn babies because their hypothalamus is continuing to develop.  The hypothalamus is the body’s homeostatic center, regulating body temperature and many other autonomic (or involuntary) functions.

Another minimally complicated condition — both from scientific and quality-of-life perspectives — is harlequin syndrome.  Like the harlequin color change just described, harlequin syndrome produces unilateral flushing and sweating in the affected person; one-half of the body will appear red while the other half is unchanged.  This is a relatively rare condition, and no definitive cause has been identified.

Based on case reports, it is hypothesized that the condition results from damage to nerve bundles in the head and neck, possibly due to trauma, autoimmune conditions, tumors, or strokes.  Once these nerve bundles are damaged, their communication with half of the body is reduced or eliminated while they maintain normal communication with the other half.  Consequently, in response to a stimulus such as increased body temperature, the half of the body with nervous communication intact will flush and sweat, and the other half of the body will remain unaffected.

Harlequin syndrome may be uncomfortable and embarrassing but is not life threatening, and many patients require no treatment.  In extreme or complicated cases, such as those involving a tumor, surgery may be performed to remove the tumor.  If the damaged nerve bundle can be identified, it can be removed via a surgical procedure called sympathectomy or treated with botulinum toxin.  With these treatments, all signaling from the nerve bundles would be disrupted, so in response to an increase in body temperature, neither side of the body would flush or sweat.

Botulinum toxin (common brand name: Botox) is produced by Clostridium botulinum and is used medically to block nerve signalling for the treatment of wrinkles, excessive sweating, and migraine headaches. It also causes the foodborne illness, botulism, which can be fatal.

The other rare and much more severe medical condition with a name inspired by the Harlequinade is harlequin-type ichthyosis.  This extremely rare genetic disease is almost always fatal, with most historical cases surviving no more than two days after birth.  The condition is characterized by the hardening of the outer layer of the skin, the stratum corneum, which forms armor-like and diamond-shaped plates.  Because the outer layer of skin is so thick and rigid, it distorts the facial features and forms red fissures in the skin between the hard plates.  This appearance led to its appellation of “harlequin-type.”

“Ichthyosis” literally means “fish skin condition.”

In the United States, the incidence of harlequin-type ichthyosis is about 1 in 500,000 live births.  The condition is inherited through an autosomal recessive pattern, which is similar to the X-linked recessive inheritance pattern of Daltonism described previously, so both parents need to have one affected copy of the gene responsible.  Through familial studies, researchers have identified a mutation in the ABCA12 gene that results in the deadly skin disease.

Autosomal recessive inheritance pattern

The ABCA12 protein is a member of the ATP-binding cassette (abbreviated ABC) transporter protein family; these channels are embedded in the phospholipid bilayer (or outer membrane) of cells and use energy from ATP (the molecule also involved with muscle contraction) to transport lipid (or fatty) molecules across the membrane.  Because the lipids move from an area of lower concentration to an area of higher concentration (in other words, against a concentration gradient), this transport requires an input of energy from ATP.  In the epidermal cells found in the skin, these lipid molecules are produced in organelles called lamellar granules. Organelles are membrane-bound areas within a cell that perform specialized functions; for example, the nucleus is the organelle that contains its genetic material.

The function of the ABCA12 protein in healthy skin (A) and harlequin-type ichthyosis (B), from Hovnanian 2005

The molecules produced and exported by the lamellar granules are used in the stratum corneum, the outermost layer of the skin, to maintain the physical barrier of the skin as well as promote the natural sloughing off of skin cells and preservation of the layers of skin underneath.  In harlequin-type ichthyosis, the genetic variations in the ABCA12 gene produce a transporter protein that is incomplete or misshapen and therefore the normal cellular functions of the stratum corneum are severely compromised.  This is called a loss-of-function mutation.

The skin is an integral part of the body’s innate immune system because it provides a powerful physical barrier to insults from pathogens like bacteria and viruses, environmental contamination, and chemical effects.  In any condition where the skin’s normal function is impaired, the individual is at a higher risk of infection.  In harlequin-type ichthyosis, the fissuring of skin between the hard plates can allow for invasion by bacteria and viruses, leading to systemic infections that can be deadly.  There is also some evidence that the production of immune factors within the lamellar granules is impaired, further compromising the immune system.

Additionally, the physical constriction resulting from the skin’s rigidity leads to difficulties with feeding, as an infant would not be able to move her lips properly to suckle, and with breathing because the skin around the chest is too tight to allow for adequate inhalation and exhalation.  Infants with this condition are immediately treated in the neonatal intensive care unit to support feeding and breathing and prevent infection.

Harlequin-type ichthyosis is primarily treated with retinoids, which are vitamin A derivatives that promote the sloughing off of the hardened skin scales and also reduce the formation of new scales.  The skin barrier is supported through applying lotions and emollients, especially those with small amounts of salt, urea, or glycerol.  Often, the hardened scales on the fingers need to be removed surgically to prevent death of the tissue from constricted blood flow.  Antibiotics are used to prevent or treat bacterial infections.  With modern intensive treatment, babies born with this once-fatal condition can survive to early adulthood.  Because this disease is so rare and treatments continue to improve, it is not yet known how much survival has increased, but the future holds promise for individuals with harlequin-type ichthyosis.

Constriction of the fingers in harlequin-type ichthyosis, from Glick et al, 2017

Repaying Attention

The naming of these medical conditions demonstrates the continued prevalence of the character of Harlequin in Western society.  Of course, this author would be remiss if they did not mention the Detective Comics character also named Harley Quinn (with 2 n’s), created by Paul Dini and Bruce Timm as a female sidekick to the Joker.  Although she has no relation to the work of Agatha Christie, the author would likely be pleased that the “Happy go lucky” Harlequin remains relevant for a new generation.

The Motley Few, Act I

**Contains major plot spoilers for The Affair at the Victory Ball.**​


“To Harlequin the invisible.”
Agatha Christie
Agatha Christie

A Singular Dedication

This dedication by Agatha Christie in her collection of short stories The Mysterious Mr. Quin is wholly unique because it marks the only time Christie dedicated one of her works to one of her fictional characters.  It is apposite, however, as Harley Quin was probably her favorite among her creations.  In her Autobiography, Christie states,

Actually my output seems to have been rather good in the years 1929 to 1932: besides full-length books I had published two collections of short stories. One consisted of Mr. Quin stories. These are my favourite. I wrote one, not very often, at intervals of perhaps three or four months, sometimes longer still. Magazines appeared to like them, and I liked them myself, but I refused all offers to do a series for any periodical. I didn’t want to do a series of Mr. Quin: I only wanted to do one when I felt like it. He was a kind of carry-over for me from my early poems in the Harlequin and Columbine series.

Unlike Hercule Poirot and Miss Marple, Harley Quin is not a detective.  Rather he is an ephemeral being, arriving at the scene of mysterious circumstances (often involving romantic entanglements) to guide Mr. Sattherthwaite (who could be considered the detective in stories involving Mr. Quin) to the truth about the situations.  Although he wears a typical dark suit, it is often described that the light hits him in certain ways to produce effects of a colorful motley or black domino mask.  Christie continues,

Harley Quin, Agatha Christie
First UK edition, 1930
Mr. Quin was a figure who just entered into a story--a catalyst, no more--his mere presence affected human beings. There would be some little fact, some apparently irrelevant phrase, to point him out for what he was: a man shown in harlequin-coloured light that fell on him through a glass window; a sudden appearance or disappearance. Always he stood for the same things: he was a friend of lovers, and connected with death. Little Mr. Satterthwaite, who was, as you might say, Mr. Quin’s emissary, also became a favourite character of mine.

The Mysterious Mr. Quin was published in 1930, shortly after the death of Christie’s brother Monty from a stroke possibly related to wounds suffered in World War I.

The character of Harley Quin only appeared in 14 stories, assembled into one collection (The Mysterious Mr. Quin) and as part of other collections (The Harlequin Tea Set and Problem at Pollensa Bay and Other Stories).  Apart from a silent movie in 1928, there has never been a cinematic or television adaptation of the works, and Harley Quin remains one of Christie’s lesser known characters.

Christie and the Harlequinade

As mentioned in What’s in a Dame?, Christie participated in amateur theatricals in her youth, and a common performance piece at the time was the Harlequinade.  Derived from the Italian Commedia dell’Arte, the Harlequinade as a pantomime, play, or ballet tells the story of Harlequin (from the Italian “Arlecchino”), a servile rogue with a predilection to aid lovers with the help of magic and invisibility.  He romantically pursues Columbine, an intelligent and compassionate servant.  His rival for her affections is Pierrot, who downplays his disappointment when spurned by playing tricks and pranks.  The character of Pierrette was a female counterpart to and love interest of Pierrot.  Punchinello and Pulcinella may also be servants but more often seem to be the masters in a situation, imposing figures with long noses and broad bellies.  The Harlequinade would tell a variety of stories with this cast of characters, often involving some scheme to separate Harlequin and Columbine, and Harlequin would use a magical stick called a “slapstick” to resolve the silly situations – this is the origin of the term slapstick humor.

harlequin, pierrot, slapstick
Commedia dell'arte characters Harlequin (left) and Pierrot, illustration on paper, c. 1874–88; in the Rijksmuseum, Amsterdam. Courtesy of the Rijksmuseum, Amsterdam; Gift of F.G. Waller, Amsterdam

Pierrot was traditionally played by an actor without a mask and wearing white make-up, which is thought to be the origin of white clown make-up. Harlequin was traditionally masked with a dark brown or black mask, suggesting African influences on the character but more likely related to systemic racism within theatre and society in relation to the character of a servant. Punchinello appears to be the origin of the character Punch from Punch and Judy puppet shows.

Inspired by these theatrical scenes, young Agatha composed a great deal of poetry in her childhood.  Some of the poems she wrote around age 17 were published in The Road of Dreams in 1924, including verses about Harlequin, Columbine, Pierrot, and Pierrette; the young Christie even set her Harlequin poems to music.  “Harlequin’s Song” describes the character with,

I pass
Where’er I’ve a mind,
With a laugh as I dance,
And a leap so high,
With a lightning glance,
And a crash and a flash
In the summer sky!
I come in the wind,
And I go with a sigh…
     And nobody ever sees Harlequin,
     “Happy go lucky” Harlequin,
Go by…
[…]
I must play my part…
     For never a soul has Harlequin,
     Happy go lucky Harlequin,
Only a broken heart…

Christie’s grandmother also owned a set of Dresden figurines from the Italian comedy, which are still part of the family’s collection. Drawing inspiration from her love of this set of characters, particularly Harlequin, Christie included them (and a similar set of figurines) in her first short story to feature Hercule Poirot, The Affair at the Victory Ball.  The story was published in Sketch in 1923 and tells the story of the murder of Lord Cronshaw at the Victory Ball, which was followed closely by the death of the actress Coco Courtenay by cocaine overdose.

A Victorious Affair

Lord Cronshaw, 25 years of age, was rumored to be engaged to Ms. Courtenay.  The pair attended the Victory Ball, dressed as Harlequin and Columbine, in the company of Punchinello (Lord Eustace Beltane, uncle to Cronshow who would inherit his title), Pulcinella (Mrs. Mallaby, an American widow), Pierrot (Chris Davidson, an acting friend of Coco’s), and Pierrette (Mrs. Davidson, Chris’s wife), in costumes inspired by Lord Beltane’s figure collection.  The mood was tense between Cronshaw and Courtenay, who requested Chris Davidson escort her home following dinner.  After accompanying the tearful actress home, Davidson returned to his flat in Chelsea.

Harlequinade figurines

At the Ball, Lord Cronshaw was scarcely seen by the party for the rest of the evening until 1:30 a.m., when he was spotted by a Captain Digby.  He asked Lord Cronshaw to rejoin the group, but he had not done so after several minutes.  A small search party was formed with Digby, Mrs. Davidson, and Mrs. Mallaby, who discovered Cronshaw stabbed to death in the supper room.  On his body was a small enamel box half filled with cocaine and with the name “Coco” inscribed in diamonds.  Also discovered tightly clenched in the Lord’s fist was a small green pompon, with ragged threads as though it had been pulled forcefully from its source.  The next morning, the body of Coco Courtenay was found in her bed, her death due to an accidental or intentional overdose of cocaine.

These facts of the case are related to Hercule Poirot by Chief Inspector Japp, whose highest talent, according to Captain Hastings, “lay in the gentle art of seeking favours under the guise of conferring them!”  Poirot visits Lord Beltane to view the original sculptures and the Davidson home to view the Pierrette costume, which had green pompons.  At the conclusion of this investigation, Poirot arranges for a Harlequinade of his own, hiring actors to portray each of the members of the Cronshaw party.  Through this elaborate reconstruction, Poirot reveals that Chris Davidson had killed Harlequin and worn a duplicate costume to pose as Lord Cronshaw at 1:30 a.m., several hours after the original Harlequin had been murdered.

Central to the dispute between Davidson and Cronshaw was the use of cocaine by Ms. Courtenay.  Lord Cronshaw strongly disapproved of the use of the drug and had demanded Coco’s supply earlier in the evening; therefore, Coco’s enamel box was found on his body.  Davidson, who supplied cocaine to Coco, murdered Cronshaw to prevent his exposure as a drug trafficker.  While escorting Coco home, he was able to provide her with more cocaine, likely encouraging her to take a larger dose out of spite for Cronshaw’s objections.  The tragic result was the death of the young actress, as well.

By viewing the figurines, Poirot was able to ascertain that the elaborate rump and ruffle of the Punchinello costume would have prevented Lord Beltane from changing into the Harlequin costume without assistance.  The two women were eliminated because Cronshaw was stabbed with a dull table knife, which would have required considerable strength.  And upon visiting the Davidson’s house, Poirot noted that the green pompon missing from the Pierrette costume was cut with scissors rather than being torn off, as the pompon in the fist of Cronshaw was; therefore, the pompon was from Pierrot’s costume.  These facts pointed directly to Chris Davidson as the perpetrator, who stabbed Cronshaw shortly following dinner and before returning Coco Courtenay home.  Presumably, Davidson had a second Harlequin costume made before the Victory Ball expressly for the commission of his crime, but this is not detailed in the story.

Chris Davidson and his wife as Pierrot and Pierrette from the Acorn adaptation, 1991

True Crime Inspiration

This story was very obviously inspired by the death of Billie Carleton (whose given name was Florence Leonora Stewart), a young actress who died from a cocaine overdose after attending a Victory Ball at the Royal Albert Hall in 1918.  Carleton was close friends with Reginald DeVeulle, a dressmaker who reportedly hosted opium parties at his house.  DeVeulle, dressed as Harlequin, attended the Victory Ball in the company of his wife Pauline (costume unknown).  While at the Ball, DeVeulle allegedly provided a supply of cocaine in a small silver or gold (reports vary) box to the actor Lionel Belcher to pass to Carleton.

Billie Carleton, National Portrait Gallery

After the festivities at the Ball, Belcher and two other actresses, Olive Richardson and Irene Castle, returned to Carleton’s apartment to continue their revelry.  It is not known what exactly transpired, but Carleton retired to bed early in the morning, and the others returned to their respective homes.  Later in the morning, Carleton’s maid noticed she had stopped snoring; the maid was unable to wake her, and she was pronounced dead a short time later.

Carleton’s death was ruled to be the result of cocaine overdose.  The police and public focused on her decadent lifestyle, as she was known to attend opium parties and her reputation had cost her at least one role.  Looking to blame a “foreign” influence on her behavior and death, Carleton’s friend and costumer Reggie de Veulle, who allegedly supplied her with cocaine, was ruled to be culpable for her death at the coroner’s inquisition but then acquitted on a formal charge of manslaughter; however, he was charged with supplying cocaine to Carleton.  A husband-and-wife duo, Lo Ping Yu and Ada Lo Ping, also received several months of jail time for their roles in supplying opium to the dead actress, among others.

Reginald De Veulle, Billie Carleton
Daily Sketch from January 2019 detailing the coroner's inquest of Billie Carleton

Christie was no doubt inspired by this sensational story from a Victory Ball in 1918.  However, her story added the murder of Lord Cronshaw in the guise of Harlequin.  Cronshaw adamantly opposed drug taking and was murdered for his beliefs, so this appears to be a way for Christie to reclaim one of her favorite characters as a noble martyr after being used as a costume by a perceived villain such as de Veulle.

Christie even borrowed the name “Cronshaw” from a previous criminal lawsuit that involved Reggie de Veulle, where one of the victims was named William Cronshaw.

Cocaine possession was illegal in Britain following the Defence of the Realm Act 1914, which was passed in 1916.

Cocaine use is featured in several other Christie novels, including Peril at End House, Hickory Dickory Death, and the Labours of Hercules.  Christie seems to have some sympathy for addicts, but her knowledge of the drug’s effects was more often used to typify the questionable morality of some of her characters.

Physiological Effects of Cocaine

Cocaine is a tropane alkaloid.  It exerts physiological effects by binding proteins within the body, most notably the serotonin transporter, dopamine transporter, and norepinephrine transporter.  These three transporters are involved in the transmission of the respective neurotransmitters from neuron to neuron in the central nervous system.  When cocaine binds, the reuptake of the neurotransmitters is reduced or eliminated, causing prolonged stimulation of the downstream neurons.

Cocaine molecule
Cocaine molecule

Inhibition of the reuptake of the neurotransmitter serotonin is the primary function of selective serotonin reuptake inhibitors (SSRIs), which are popular antidepressant medications.

Additionally, cocaine binds to voltage-gated ion channels in the heart, which can result in cardiotoxicity.  These channels are present on cellular membranes and control the amount of electrolytes present within cells versus between cells.  Electrical changes in the cellular membranes control whether the channels are open or closed.  Therefore, an interruption in the function of these channels can lead to deadly electrolyte imbalances.

Electrolytes are ionic (or positively or negatively charged) forms of mineral elements, for example, sodium (+1), potassium (+1), and calcium (+2).

Research has shown that the interaction of cocaine with dopamine receptors is the primary mechanism that drives addiction.  In animals genetically manipulated such that their dopamine receptors do not bind cocaine, addictive behaviors do not manifest when the animals are provided and/or deprived of cocaine.  However, the interaction between cocaine and the serotonin receptor may cause convulsions, so the displacement of serotonin does play a role in cocaine toxicity.  Lastly, the inhibition of norepinephrine signalling by cocaine can lead to rapid increases in blood pressure.

Cocaine also interacts with cholinergic receptors and prevents reduction in heart rate.  This interaction would cause an increase in heart rate (similar to atropine as described in Tuesday Night Fever).  Coupled with the effect on voltage-gated channels and the increase in blood pressure from norepinephrine inhibition, damage to the heart is a central component of cocaine toxicity.  Because the neurotransmitter receptors have a higher affinity for cocaine (in other words, cocaine can bind strongly at lower concentrations), the central nervous system is affected first; for example, the user begins to have seizures.  With higher doses or concentrations of cocaine, the voltage-gated ion channels are then affected, and the cardiotoxic effects of cocaine are seen.  The interference of cocaine with voltage-gated sodium, potassium, and calcium channels will cause cardiac arrhythmias, which are abnormal changes in heart rate.  These arrhythmias can cause sudden cardiac death in cocaine users, even without any pre-exisiting cardiac conditions.

Christie does not provide specific details of Coco Courtenay’s death (nor other characters who perish from cocaine), but it is plausible that the victims suffered sudden cardiac death or a severe seizure.  At Reggie de Veulle’s trial, a doctor testified that Billie Carleton had cocaine present in her nostrils and died as a result of an increase in blood pressure and the formation of blood clots in her heart due to the cocaine, which starved her body of oxygen and led to death.  Interestingly, the doctor who attended Carleton the morning of her death stated he administered strychnine (and brandy) in an attempt to resuscitate the actress.  She was 22 years old at the time of her death.

calcium channel, potassium channel, cholinergic receptor
Some molecular targets of cocaine

Rigor Mortis

Another intriguing scientific principle that features in The Affair at the Victory Ball is rigor mortis, the stiffening of muscles following death.  Because Chris Davidson donned a harlequin costume and impersonated Lord Cronshaw within 10 minutes of his cohorts finding the body, a doctor testified that the stiffening of Cronshaw’s body was abnormal.  However, because Cronshaw had been killed several hours prior, this was actually the natural process of rigor mortis.  In addition to suggesting the time of death, it also led to the discovery of the important clue of the green pompon, which was clenched in Cronshaw’s fist.

Skeletal muscle diagram

Immediately following death, all muscles in the body are fully relaxed.  Within the first hour, some of the smaller muscle groups (such as the jaw and eyelids) begin to stiffen, followed by larger muscle groups.  The timing of onset and development of rigor mortis can vary considerably due to factors such as the ambient temperature, and rigor mortis develops more quickly in higher temperatures.

In a living body, the functional unit of skeletal muscles, myofibrils, comprise the myofilaments actin and myosin.  To contract, they are acted upon by adenosine triphosphate (ATP), which is an enzymatic cofactor that is involved in intracellular energy transfer.  In the presence of ATP, actin and myosin form the compound actomyosin, which physically shortens during muscle contraction.  Shortly after death, the production of ATP ceases, and the crossbridges formed between actin and myosin no longer break down.  This results in the muscle stiffening and shortness that is characteristic of rigor mortis.  

An enzyme is a protein that catalyzes chemical reactions by reducing the energy required, and they are not consumed by the reaction. An enzymatic cofactor is a molecule that binds to a specific region of an enzyme and is required for the normal function of the enzyme.

Diagram of muscle contraction. After death, ATP is not available for Step 4; therefore, the muscles remain contracted.

Rigor mortis may take 6 to 18 hours to fully take effect but can occur more quickly in higher temperatures.  If the individual who dies was engaged in vigorous exercise, such as a struggle, before death, the onset may even be more rapid; this was likely the case with Lord Cronshaw as he attempted to fight off Chris Davidson.

The discovery of the green pompon clasped tightly in Cronshaw’s fist may be less scientifically plausible.  A theory of “cadaveric spasm” posits that rigor mortis can instantly appear following death based on the appearance of dead bodies during World War I and World War II.  However, there remains no credible biological explanation for such a phenomenon, and it is more likely that rigor mortis set in with the typical delay during the wars, but the bodies had continued to be affected by explosions on the battlefield until it fully set in. 

rigor mortis, cadaveric spasm
Leaves clasped within the hands of a body recovered from water, from Toskos and Byard, 2016

Consequently, it is highly unlikely that Lord Cronshaw’s fist remained tightly clasped around the pompon from the time just before his death until his discovery.  Because all muscles relax after death, he would have dropped the pompon, but as long as it remained just beneath the palm of his hand, he would have re-grasped it when rigor mortis took effect.  This is possible but somewhat unrealistic given the short period of time between his death and the discovery of his body.  Nevertheless, the inclusion of this plot point illustrates Christie’s basic understanding of rigor mortis.

The next blog post will further explore the characters of Harley Quin and Mr. Satterthwaite and describe medical conditions whose names are derived from the character of Harlequin.

Tuesday Night Fever

**Contains major plot spoilers for Ingots of Gold, The Thumb Mark of St. Peter, and The Blue Geranium and minor plot spoilers for The Companion and The Big Four.**​


“Human nature is much the same everywhere, and, of course, one has opportunities of observing it at closer quarters in a village.”
Miss Jane Marple

An Acidulated Spinster

Although the first full-length novel with Miss Jane Marple as the detective was published in 1930 (Murder at the Vicarage), the character initially appeared in print in a series of 6 short stories Christie wrote for a magazine in 1928.  In 1932, an additional 6 stories were added, and the compilation was published as The Thirteen Problems (UK) or The Tuesday Club Murders (US).

In her Autobiography, Christie reflects,

The original title was Thirteen at Dinner, which was used the following year for a different Christie novel featuring Hercule Poirot and alternatively titled Lord Edgware Dies.

Murder at the Vicarage was published in 1930, but I cannot remember where, when or how I wrote it, why I came to write it, or even what suggested to me that I should select a new character—Miss Marple—to act as the sleuth in the story. Certainly at the time I had no intention of continuing her for the rest of my life. I did not know that she was to become a rival to Hercule Poirot.

She continues,

I think it is possible that Miss Marple arose from the pleasure I had taken in portraying Dr. Sheppard’s sister in The Murder of Roger Ackroyd. She had been my favourite character in the book—an acidulated spinster, full of curiosity, knowing everything, hearing everything: the complete detective service in the home.

A Rag-Tag Group

The Thirteen Problems is a collection of short stories, as told by a group of companions gathered in the fictional village of St. Mary Mead.  In addition to Miss Marple, the members of the “Tuesday Night Club” include Raymond West, Marple’s nephew and a novelist; Joyce Lempriere, a painter who is romantically involved with Raymond; Mr. Pettigrew, a local solicitor; Henry Clithering, former commissioner of Scotland Yard; and Dr. Pender, an elderly clergyman.  With the addition of the last 6 stories, the characters of Major and Dolly Bantry were added, and they would be featured in subsequent Marple novels.

The stories recounted by the companions are tales of poisoning, mysterious rituals, theft, murder, blank wills, and espionage — all Christie mainstays.  In each of the stories, Miss Marple surprises the others by arriving at the solutions to the mysteries by drawing parallels to her observations of life in St. Mary Mead.  In Ingots of Gold, Miss Marple points out that one of the offenders was pretending to be a gardener, which is obvious to her as gardeners do not work on Whit Monday, and in The Companion, Miss Marple recalls the story of a Mrs. Trout, “only a person–not a very nice person–in the village”:

Source: Collins Crime Club
I must confess it does remind me, just a little, of old Mrs. Trout. She drew the old age pension, you know, for three old women who were dead, in different parishes… It’s just Mrs. Trout over again. Mrs. Trout was very good at red herrings, but she met her match in me.

This blog post will focus on two stories within the collection: The Thumb Mark of St. Peter and The Blue Geranium.  Both stories involve poisoning and have been mimicked or reproduced in some interesting true crime cases.

St. Peter's Thumb

The Thumb Mark of St. Peter marks Miss Marple’s contribution of a mystery story to the Tuesday Night Club.  She recounts a story involving her niece, Mabel, whose husband Geoffrey suddenly dies.  Rumors circulate that Mabel has poisoned her husband, whom a doctor concludes to have died from eating poisoned mushrooms.  Mabel reveals that she had bought arsenic at the chemist’s the morning of her husband’s death with the intention of poisoning herself.  The household staff report that in the evening, Geoffrey was in great agony and unable to swallow; he could only speak in a garbled voice, and he rambled about “a heap of fish”. 

Through the persistence of Miss Marple in her investigation, the husband’s body is exhumed and tested for poisoning, but “there was nothing to show by what means [the] deceased had come to his death.”  Miss Marple speaks with the pathologist, who concedes that the death may have been caused by a strong vegetable alkaloid.  Deep in contemplation, she stumbles upon a fish monger’s shop, which draws her mind back to the “heap of fish”.  She reinterviews the cook, who states that Geoffrey had said “pile” rather than “heap” and referred to a specific fish beginning with the letter “C”.  Miss Marple consults an index of drugs and discovers the compound pilocarpine, which could be easily misconstrued as a “pile of carp” or “heap of fish”. 

Given the use of pilocarpine as an antidote to atropine poisoning, Miss Marple ascertains that the husband’s elderly father had actually committed the murder by emptying his bottle of eye drops (containing atropine sulfate) into his son’s water glass.  When confronted, the old man confesses his crime, which he did to prevent Geoffrey from institutionalizing him.  At the conclusion of her story, Sir Henry Clithering tells Miss Marple, “I shall recommend Scotland Yard to come to you for advice.”

To Cut the Thread of Life

Atropine is a plant alkaloid derived from Atropa belladonna, or deadly nightshade, and is named after Atropis, one of the three fates in Greek mythology whose role was to cut the thread of life.  The name “belladonna” (meaning “beautiful lady” in Italian) originates from the use of the juice of the berries by women to dilate their pupils in order to enhance their attractiveness.  Although excessive use can cause blurred vision and blindness, this function of atropine is still used in ophthalmology to this day to allow for eye examinations and relieve pressure buildup.

Atropa belladonna

In The Big Four, Hercule Poitrot uses belladonna in his eyes to disguise himself as his “brother”, Achille Poirot, an invention to elude defeat by the novel’s villains.

Due to its chemical structure, atropine is not highly water soluble; therefore, a salt form is generally used in medications, such as the atropine sulfate found in the elderly father’s eyedrops in The Thumb Mark of St. Peter. As discussed in Dressed to the Strychnines, Act II, salts are formed by the ionic pairing of compounds rather than the sharing of electrons in covalent bonds.  Consequently, there is no change to the action of atropine in its salt form, rather it is more easily absorbed across mucous membranes and the gastrointestinal tract.

Once in the bloodstream–and similar to strychnine–atropine acts as an antagonist to the neurotransmitter receptors of acetylcholine, which are also called muscarinic receptors.  Acetylcholine is the primary neurotransmitter of the parasympathetic nervous system, and its signaling modulates the production of bodily fluids such as mucus in the upper gastrointestinal tract, lungs, heart, and sweat glands.  When atropine antagonizes the muscarinic receptors, the production of fluids diminishes; another medicinal use of atropine sulfate is to decrease mucous secretions in the bronchioles of the lungs prior to surgeries to prevent any blocking of the airway.

Action of antagonists and agonists

The use of atropine sulfate in eyedrops may treat a condition called miosis, which is excessive constriction of the pupils, or anterior uveitis, which is inflammation of the uvea or iris.  Christie does not note the specific ophthalmologic malady suffered by the father in The Thumb Mark of St. Peter, but by distilling atropine in the eye, the muscles that control the iris are paralyzed, dilating the pupil and relieving the build-up of pressure.  By keeping the dose administered low, the effect of blurred vision is temporary, though the dilation of the pupils may persist for several days.

Anatomy of the heart, including the sinoatrial node

When atropine is ingested in large amounts (approximately 10 to 100mg, depending on the form), its effects are lethal because it quickly inhibits the signaling of the parasympathetic nervous system to the heart.  Typically, acetylcholine released by the parasympathetic nervous system via signaling through the vagus nerve acts on the sinoatrial node of the heart, which controls the heart rate.  In the presence of acetylcholine, the heart rate is slowed to less than 100bpm.  When acted upon by the antagonist atropine, the heart no longer receives the signals to slow its rate of beating. This increase in heart rate leads to an increase in respiratory rate, coupled with a decrease in fluid secretions.  The condition is accompanied by hallucinations, muscle convulsions, and coma, and can lead to death.

The poison scopolamine has similar effects as atropine and was the poison allegedly used by Dr. Hawley Crippen to dispatch his wife in a well-known historical true crime. Christie also included scopolamine as a murder weapon in her first play, Black Coffee.

A Pile of Carp

Like atropine, pilocarpine is a plant alkaloid, and it is derived from the leaves of Pilocarpus pinnatifolius.  It acts in direct opposition to atropine, as it is an agonist of the same receptors.  When it binds to acetylcholine receptors, it exerts the same effect as the neurotransmitter, increasing mucous secretion and slowing the heartbeat.  Coincidentally, pilocarpine is also used medically in the form of eyedrops to treat glaucoma.  

Because of their opposing actions, either pilocarpine or atropine can be used as an antidote to poisoning with the other compound.  As in The Mysterious Affair at Styles, Christie uses her specialized knowledge from her time in the dispensary to create a clever poisoning mystery.

Source: Koehler's Medizinal Pflanzen (1883-1914)

Meanwhile in True Crime...

In what may be the true crime case that was most directly inspired by a work of Christie’s, an elderly French couple was killed by their nephew, who had added atropine from a bottle of eyedrops to a bottle of wine he gave the couple.  The nephew, Roland Roussel, knew his aunt and uncle did not typically consume alcohol and assumed that they would share the wine with a woman who often visited and whom he blamed for the death of his mother.  Unfortunately, the aunt and uncle decided to drink the bottle of wine on Christmas Day.  The uncle died, and the aunt was comatose.

A neighbor discovered the couple, and doctors first speculated that food-borne illness was to blame.  A few days later, the couple’s son-in-law and a carpenter went to the house to place the uncle’s body in a coffin.  As there was still wine remaining in the bottle, both men drank a small amount and were rendered unconscious.  They received proper medical treatment, and the wine was tested for contaminants, revealing the addition of atropine to the bottle.  With this major clue, investigators directed their attention to Roland Roussel.  Upon searching his apartment, they discovered a copy of The Thirteen Problems with certain passages in The Thumb Mark of St. Peter underlined.  No further information about the fate of Roussel has been published.

In a case of attempted murder, Paul Agutter, a biology lecturer at Edinburgh University, added atropine to a bottle of tonic water that he used to make his wife a gin and tonic.  She complained of the bitter taste and only drank a small amount, but she ingested enough of the poison to become seriously ill.  So elaborate was the husband’s plan that he added atropine to multiple bottles of tonic water and returned them to the shelf of a local supermarket.  Although each of these bottles had smaller quantities than the bottle used for Mrs. Agutter’s drink, 8 people were hospitalized after consuming tonic water purchased from the supermarket.  

Closed-circuit television in the market captured Agutter placing the bottles on the shelf, and an employee also observed him doing so.  Agutter’s attempt to manipulate the authorities into suspecting that a lunatic was poisoning bottles of tonic water and that his wife just happened to be a victim was not successful; he served 7 years in prison for attempted murder.  The wife recovered.

Paul Agutter and the "Safeway Poisoning"

Blue Flowers

Another story in The Thirteen Problems also involves poisoning; however, the toxin in this instance is cyanide.  In The Blue Geranium, Dolly Bantry shares what she considers a supernatural tale with Miss Marple and some other members of the Tuesday Night Club.  The tale centers around the wife of family friend George Pritchard, who is never given a Christian name.  Mrs. Pritchard is a difficult, demanding woman, with an unspecified medical condition that renders her somewhat disabled.  A series of nurses live with the couple to care for Mrs. Pritchard, but each is dismissed after a short time.

Mrs. Pritchard is also partial to spiritual mediums.  One of the more competent nurses, Nurse Copling, arranges for a visit from Zarida, Psychic Reader of the Future.  Following the visit, Mrs. Pritchard is distraught, smelling frequently from her bottle of smelling salts.  She reports that Zarida says there is evil and danger present in the house.  More specifically, the psychic tells Mrs. Pritchard, “Blue flowers are fatal to you–remember that.”  Two days later, Mrs. Pritchard receives a letter from Zarida that states,

I have seen the future. Be warned before it is too late. Beware of the Full Moon. The Blue Primrose means Warning; the Blue Hollyhock means Danger; the Blue Geranium means Death…

The morning after the next Full Moon, which is a few days later, Mrs. Pritchard rings her bell violently to report that one of the pink primroses illustrated on her wallpaper had turned blue.  Before the next Full Moon, Mrs. Pritchard has her husband and nurse both study the wallpaper and lock the door to her room.  The next morning, one of the hollyhocks on the wallpaper has turned blue.  Although Nurse Copling is alarmed and asks George to move Mrs. Pritchard from the house, he retorts, “If all the flowers on that damned wall turned into blue devils it couldn’t kill anyone!”

The morning after the following Full Moon, there is no bell ringing heard from Mrs. Pritchard’s room.  George chisels the door open to discover Mrs. Pritchard’s lifeless body in bed.  She has dropped her bottle of smelling salts on the bed, and one of the pink geraniums on the wallpaper has turned blue.  There is a slight smell of gas in her room but not enough to have led to death.  Although there is suspicion that George murdered his wife, there is no indication following her autopsy that there was any foul play.  It is generally accepted that the woman died of fright.

Of course, Miss Marple does not accept this explanation.  She states,

Well, if I did [wish to kill someone], I shouldn’t be at all satisfied to trust to fright. I know one reads of people dying of it, but it seems a very uncertain sort of thing, and the most nervous people are far more brave than one really thinks they are. I should like something definite and certain, and make a thoroughly good plan about it.

The reassurance that pink flowers had turned blue (rather than yellow flowers) further cements her idea.  She reveals that the culprit is Nurse Copling, and the changing colors of the flowers on the wallpaper was accomplished through the use of litmus paper, which nurses often carry.

Litmus paper contains the molecule 7-hydroxyphenoxazone, a weak acid which changes to a blue color at an alkaline (basic) pH of 8.3 or higher.  When a strong base is added, the molecule donates a hydrogen atom, and the resulting conjugate base has a blue color.

Miss Marple reveals that Nurse Copling has replaced Mrs. Pritchard’s smelling salts with potassium cyanide, which is visually indistinguishable.  Confident that Mrs. Pritchard would smell at them when faced with the blue flowers, Nurse Copling stages the visit from Zarida and a follow-up letter to distress the poor woman.  The strong ammonia fumes from the smelling salts, which are basic or alkaline, would cause the litmus paper that Nurse Copling had pasted on top of the flower wallpaper to turn blue.  While George Pritchard calls for a doctor, the nurse quickly substitutes the cyanide bottle with standard smelling salts and turns on the gas a small amount to hide the scent of bitter almonds typical of cyanide.  Miss Marple speculates that Nurse Copling has fallen in love with George Pritchard, although he does not return her affections.

Because cyanide is prevalent throughout Christie’s work, an in-depth discussion of this poison will be reserved for a future post.  Briefly, cyanide is rapidly converted into hydrogen cyanide in the gastrointestinal tract, and this form is readily absorbed into the bloodstream.  Cyanide displaces oxygen in hemoglobin molecules, which serve to transport oxygen from the lungs throughout the body.  With this method of transportation, cyanide can be delivered to cells in various body systems. 

Cytochrome c oxidase

Once in the cell, cyanide binds to the enzyme cytochrome c oxidase; this enzyme catalyzes the final step of oxidative phosphorylation (or aerobic metabolism) in the mitochondria.  Cyanide is an antagonist to cytochrome c oxidase; after it binds, the chemical reactions responsible for generating cellular energy stop, resulting in cell death.  Cyanide can kill within minutes to hours due to this widespread cell death.

The Auburn Cyanide Murders of 1986

Although this author was unable to locate any true crime cases that involved the substitution of smelling salts with potassium cyanide, there are several cases where cyanide has been added to otherwise safe medications.  Following the Chicago Tylenol cyanide poisonings in 1982, Bruce Nickell and Susan Snow were killed by Excedrin capsules poisoned with cyanide in Washington state.

Although Bruce’s death was first, it was not until after Susan died that his death was attributed to cyanide poisoning.  Susan was 40 years old and suffered from headaches but was otherwise healthy.  On the morning of 11 Jun 1986, Susan took two capsules of Extra-Strength Excedrin and was discovered collapsed in the bathroom a short time later by her daughter.  She was clinging to life but died a short time later at the hospital.

During Susan’s autopsy, the Assistant Medical Examiner smelled the distinctive bitter almond smell that accompanies cyanide.  A blood test confirmed that Susan had died from acute cyanide poisoning.  Investigators were baffled as to the source, until Susan’s twin sister reached for some Excedrin on the day of Susan’s funeral.  She noted to investigators that Susan usually purchased Excedrin tablets, and it was unusual for her to have Excedrin gel capsules.  Tests of the remaining capsules in Susan’s bottle of Excedrin showed that three more capsules contained lethal quantities of cyanide.

Susan Snow

The ability to smell cyanide is a genetic trait, which has been shown to be prevalent in approximately 50% of people. 

The testing of Excedrin for cyanide expanded to include other bottles from the same lot number as Susan’s.  An additional tainted bottle was discovered at a supermarket in Kent, Washington, and Bristol-Myers, the manufacturer of Excedrin, issued a recall for all bottles of Extra-Strength Excedrin in the Seattle, Washington area.  Several pharmaceutical companies banded together to offer a $300,000 reward for the apprehension of the person responsible for poisoning the capsules.

Once this information about the tainted Excedrin was publicized, 42-year-old Stella Nickell phoned authorities, stating that her husband Bruce had recently died after taking four Excedrin capsules from a bottle with the same lot number that was the target of the recall.  Bruce was 52 years old and a heavy smoker, and doctors had concluded he died from complications related to emphysema.  With the new information from Susan Snow’s death, investigators tested Bruce’s body for traces of cyanide, which were indeed present.

Bristol-Myers responded by recalling all bottles of Excedrin capsules in the United States, quickly followed by a recall of all of the company’s nonprescription capsule medications.  A few days later, investigators discovered a cyanide-tainted bottle of Anacin-3, an Excedrin competitor, and Washington state issued a 90-day ban on the sale of all nonprescription capsule medications.

Bruce and Stella Nickell

The contaminated medications were sent to the FBI Crime Lab in Washington, D.C., for examination.  The cyanide salt that had been added to the medications contained small granules of a green substance.  Additional testing showed that the green substance was the commercial product Algae Destroyer, which is used to clean home aquariums.  Investigators surmised that the culprit must have used a container to crush or mix the cyanide that had been previously used to crush Algae Destroyer tablets.

Around the same time, investigators were focusing on Stella Nickell.  In addition to owning several tropical fish aquariums, the widow had inherited a total of $175,000 from Bruce’s multiple life insurance policies.  Document examiners at the FBI had determined that Bruce’s signature had been forged on the applications, and Stella inherited an additional $100,000 now that her husband’s death was determined to have been accidental.  Furthermore, Stella had two tainted Excedrin bottles out of the total of five that had surfaced throughout the country, and she initially refused to undergo a polygraph examination, which she subsequently failed.

The clues continued to accumulate.  Stella’s 27-year-old daughter Cindy approached authorities, recalling that her mother told her several times that she wanted to kill Bruce as she had become bored in the relationship.  She admitted to trying to kill him with foxglove, after which he was sick for a few days and then recovered.  Cindy also stated her mother had researched poisons at the library.

Foxglove is a source of the poison digitalis, which Christie used in several novels and stories including Appointment with Death, Postern of Fate, and The Herb of Death in The Thirteen Problems.

Records from the Auburn Public Library were subpoenaed, and the FBI detected Stella Nickell’s fingerprints on pages related to cyanide in books such as Deadly Harvest.  This evidence, along with Stella’s financial gain, Cindy’s testimony, and the manager of a tropical fish store positively identifying Stella as a purchaser of Algae Destroyer, led investigators to arrest Stella for the double murder in December 1987.

Stella was charged with product tampering that resulted in the deaths of Bruce Nickell and Susan Snow under the 1983 Federal Anti-Tampering Law, which was a result of the Chicago Tylenol cyanide poisonings.  Jurors found her guilty, and she received two life sentences.  Her current release date is 10 Jul 2040, when she will be 97 years old.

Night Train to Perdition, Act III

See Night Train to Perdition, Act I, for a summary of Murder on the Orient Express, and Night Train to Perdition, Act II, for a summary of related true-crime cases, including the kidnap and murder of Charles Lindbergh, Jr.  The post you are reading details the forensic science responsible for the capture and conviction of one of the kidnappers, in particular the wood evidence provided by the ladder used in the kidnapping.

The Wooden Witness

As noted in Act II, two key pieces of evidence were discovered immediately following the crime at the Lindbergh estate: a handwritten ransom note and a custom ladder.  In their preliminary examination of the three-sectional ladder, the investigators postulated that the user was neither too tall nor too short and was left handed.  The left handedness of the user was based on the pattern of saw blade cuts in the wood as well as the placement of the ladder to the right of the nursery window, which would allow the user to navigate entry into the nursery from his left side.  The runners used in the ladders appeared to resemble wood crates that were used to protect bathtubs during transit, and police reported that the ladder was similar to those used with pipe organs.

However, these initial theories brought investigators no closer to an actionable lead.  Dr. Erastus Mead Hudson, an independent fingerprint expert and specialist in chemistry and bacteriology proposed to examine fingerprints that may have been left by the kidnapper or kidnappers on the ladder.  Instead using fingerprint powder, which was the custom practice at the time, Hudson used silver nitrate (AgNO3) to identify prints.  Unfortunately, the ladder had been handled so extensively since the kidnapping that there were approximately 500 latent fingerprints present, which could not be used to identify any criminals.

Silver nitrate interacts with salt deposits found in human sweat and shed with fingerprints, which can then be visualized with ultraviolet light.

In the middle of 1932 and still at a loss for any leads, the investigators turned to the federal government for assistance.  They sent the ladder, a chisel that was also found at the Lindbergh estate, and a soil sample to the Department of Justice.  Drawing on the expertise within various federal departments, the DOJ sent samples from the ladder to the US Forest Service, of which 7 samples were sent to the Forest Products Laboratory in Madison, WI, a joint research venture with the Forest Service.  Upon receipt, FPL Director Carlisle P. Winslow told Arthur Koehler, considered the nation’s top wood identification expert, to disregard all other projects and immediately identify the source of the wood in the Lindbergh kidnapping ladder.  To do so, Koehler would apply his specialty in xylotomy, which is the art of preparing sections of wood for microscopic examination.

The Wood Expert

Arthur Koehler had established himself as a skilled xylotomist and had been serving as an expert witness in criminal trials following his promotion to the Head of Wood Technology at the FPL.  He had recently testified in the murder trial of John Magnuson regarding the source of wood used by the criminal to encase a bomb, which led to a conviction.  Koehler had even offered his assistance to Lindbergh after the kidnapping with a personal letter:

I read further in the newspaper about that homemade ladder left behind by the fellow who had done the crime and I grew excited.  You see, that ladder, because it was made of wood, seemed just like a daring challenge.

Within a few days after that I wrote a letter to the Lindbergh baby’s father, saying I thought it might be possible to trace that ladder’s members until the wood matched up with other wood so as to compromise the man involved.  Of course, I’m no Sherlock Holmes, but I have specialized in the study of wood.  Just as a doctor who devotes himself to stomachs or tonsils or human vertebrae narrows down his interests to a sharp focus on the single field of his pet passion, so I, a forester, have done with wood.

He did not receive a response from Lindbergh. 

Less than one week after receiving samples from the kidnapping ladder, Koehler had identified the various sources as Douglas fir, paper birch, Ponderosa pine, and Southern pine through comparisons with the FPL’s library of wood specimens.  After submitting his report to the Department of Justice, Koehler wanted to continue helping with the investigation, his goal to make the ladder a “wooden witness.”

The Wooden Autopsy

In early 1933, the New Jersey State Police would take Koehler up on his offer.  Koehler was given full access to the ladder, which he dismantled to perform an “autopsy.”  Each rung and rail was numbered, measured, and calipered.  Koehler identified the source for each piece and closely examined the components for marks made during the assembly of the ladder.  As relatively few sources of wood were used to construct the ladder, Koehler concluded “that the maker had a limited amount of material to choose from.”

Among all the pieces of the kidnapping ladder, Rail 16 seemed to offer the greatest potential for confirmatory evidence to match to a criminal.  Rail 16 was North Carolina pine (the same as Rails 12 and 13), but it was more knotty and had not been machine planed.  Rather, it had been hand-planed on both edges, leading Koehler to believe that the rail was worked down from a wider piece of wood:

Diagram of the Lindbergh kidnapping ladder

Why he planed both edges of rail 16 is a mystery unless it was rough edged to begin with.  The edges were not always at right angles to the face, and scratches made by the plane wobbled back and forth along the edge…the scratches left by a hand plane on both edges of this rail were exactly the same as those on one side of each of the [cleats], proving conclusively that they were made by the same plane, and presumably at approximately the same time, probably when the ladder was made.

Furthermore, Rail 16 had four nail holes that had been made by square-cut or 8-penny iron nails, which had been phased out of production by the end of the 1800s in favor of cheaper wire nails made from soft steel.  In the 1930s, square-cut nails were still used in home construction, and the regular spacing of the nail holes in Rail 16 suggested they may have come from a building.

Keen to pursue multiple avenues of investigation, Koehler also fully characterized the marks from the machine planer used on Rails 12 and 13.  He sent letters to the known manufacturers of wood planers to inquire as to which mills they may have sold the characteristic planers, and then solicited the mills for samples for examination.  From April to September 1933, Koehler sent a total of 1596 requests and received 23 samples.  Despite the small number of samples, he was able to identify Rails 12 and 13 as having been planed in a mill in South Carolina by examining the planer knife marks microscopically and measuring the marks to 1/100th of an inch.  Ultimately, Koehler was unable to trace the kidnapper(s) based on Rails 12 and 13 because the Bronx lumber yard from which it was likely sold was a cash-only business.

Meanwhile...

At the same time that Koehler was examining the wood of the kidnapping ladder, the police were actively tracing the ransom money.  The $50,000 that was paid on behalf of the Lindbergh family by the go-between John Condon primarily comprised $20 and $10 gold certificates.  Elmer Irey, an IRS accountant, proposed this mechanism to allow for easier tracing of the ransom money as the gold certificates were being phased out of circulation.  The remaining ransom money was $5 bills with red seals and red serial numbers.  All of the ransom money was printed in 1928, and a list of the serial numbers was sent to banks across the country.

Lindbergh kidnapping ransom money
1928 $10 gold certificate

Bills from the lot of ransom money would occasionally surface over the year and a half following its payment in 1932, most often in New York City.  On 17 Sep 1933, a man paid for 98 cents of gasoline with a $10 gold certificate at a gas station in Manhattan.  The station manager questioned the legitimacy of the bill and wrote down the man’s license plate number in its margin, in case the bank refused to deposit it.  The manager questioned the customer about the bill, who was reported to reply, “I have a hundred more just like it.”

The license plate number was traced to Bruno Richard Hauptmann, an unemployed carpenter who was pulled over for a search shortly after leaving his house in the Bronx.  When detectives found money in his wallet with serial numbers matching the ransom money, he was arrested.

The Wooden Key

Upon hearing of Hauptmann’s arrest, Koehler suggested that investigators take note of any lumber in his house that may have been used for Rail 16 as well as for any woodworking tools.  In their first search of the house, investigators found a total of $13,750 of the ransom money and an automatic revolver concealed in wooden 2×4’s in the garage; they also found a large wooden plane with a nicked blade that could have been used in the construction of the ladder.

At the time of Hauptmann’s arrest, a news article reported that he once worked odd jobs at the National Lumber and Millworker Corp in the Bronx, where Koehler had traced Rails 12 and 13.

Attic floor of Richard Hauptmann
Missing wood from Hauptmann's attic floor (Source: Dr. Regis Miller/Forest Products Laboratory)

During a second search of Hauptmann’s attic, the investigators noted that the flooring comprised 27 pieces of 1×6 North Carolina pine.  The final board on the south side was not the same length as the others, and they were able to discern that a piece approximately 8 feet long had been removed, leaving traces of saw marks and saw dust.  A sample of the remaining board and the nails that had been used to connect the board to the joist were provided to Koehler for comparison.

Koehler observed nicks in the largest knife of the plane recovered from Hauptmann’s house that produced marks exactly matching those on Rail 16 and the pine rungs of the ladder.  He concluded, “There is no question but [that] the rungs and rail were planed with that plane.”

The nails removed from the boards in Hauptmann’s attic fit into the holes in Rail 16 precisely, which lead Koehler to conclude “the board probably was removed from some of Hauptmann’s previous work either for others or for himself.”  Koehler testified before the grand jury at the Hunterdon County Courthouse in Flemington, New Jersey, to these points.  Along with testimony pertaining to the ransom note, ransom money, and various eyewitnesses, the grand jury found enough evidence to indict Hauptmann for the murder of Charles Lindbergh, Jr.

Meanwhile, Koehler continued his examination of Rail 16 in comparison to the wood removed from Hauptmann’s attic.  He and the investigators took Rail 16 to Hauptmann’s attic, where it fit snugly into the place of the missing board.  Koehler reflected that “Such a result could not happen as a mere coincidence.”  Koehler had calculated the probability of all 4 nail holes matching the joists in Hauptmann’s attic perfectly as 1/1016, and he dismissed the possibility that this was mere circumstantial evidence.

1/1016, or 1 in 10 quadrillion, is the probability of 2 people randomly picking the same word out of 110 billion average-sized books.

Finally, he compared the grain, which is the appearance of the natural rings of a tree when it has been cut lengthwise to form a board: 

It is a pattern that is always varied and yet the pattern of the grain in the ladder rail and floor board matched as perfectly as if the interrupted curving lines they plotted years ago had been etched within the tree just to be a trap for anyone who dared so to misuse wood as to form it into a kidnap ladder.

Rail 16 matched to Hauptmann's attic floor
The wood of Rail 16 matched with Wood from Hauptmann's attic (Source: Dr. Regis Miller/Forest Products Laboratory)

Every tree within itself has written all its history.  The growth in spring shows white and pithy, but in the summer the slower growth becomes, in most trees, darker tissue.  This is repeated year by year, and that is why these rings seem double and confuse those who try to say a tree is such and such an age.  Count the band of white and black as one year’s growth.  The board end of the piece of flooring that had been robbed to make a ladder showed its rings quite clear, and so did the ladder rail.  A gap of one and three-eighth inches had been trimmed off, yet the rings matched.

The Wooden Evidence

At Hauptmann’s murder trial, Koehler testified his findings regarding Rail 16, but he was challenged by one of the defense lawyers, who stated, “We say that there is no such animal known among men as an expert on wood.  That is not a science that has been recognized by the courts; that is not in a class with handwriting experts, with fingerprint experts or with ballistic experts.  That has been reduced to a science and is known and recognized by the courts.”  The judge allowed the defense council to cross-examine Koehler to ascertain the extent of his credentials.  At the end of Koehler’s lengthy exposition regarding his publications in the field of wood science, the judge confirmed he was indeed a wood expert.

Koehler provided the court with complete details regarding his examination of the kidnap ladder, in particular Rail 16’s nail holes and grain.  His xylotomical examination of the wood source and grain was essential to tying Hauptmann to the ladder used in the Lindbergh kidnapping.  Following the testimony, Koehler was lauded as “the only real detective (in the case)” by the Reading, Pennsylvania Times, and The New York Post wrote, 

The Hauptmann trial may go down in legal history less as the most sensational case of its time than as the case which brought legal recognition to the wood expert on par with handwriting, fingerprint and ballistic experts.

After 42 days of testimony from Koehler and others involved in the Lindbergh case, the jurors retired to deliberate on the verdict of Hauptmann.  Less than 12 hours later, the jury returned with a verdict of guilty.  The judge passed down a death sentence to the convicted murderer of Charles Lindbergh, Jr.  Koehler’s testimony stood up to several appeals by Hauptmann, and on 03 Apr 1936, his death sentence was carried out by electric chair.  Hauptmann never confessed to the crime and never indicated if other kidnappers were involved.

Koehler continued working as a wood identification expert but never in so sensational a trial as the Lindbergh case.  He died in his home on 16 Jul 1967 at the age of 82.  Although wood evidence continues to be valuable to forensic science, it has never again been at the forefront of a crime as in the Lindbergh kidnapping.

Night Train to Perdition, Act II

**Contains major plot spoilers for Murder on the Orient Express .**​

See the previous post, Night Train to Perdition, Act I, for background on Murder on the Orient Express as well as a synopsis of the book.  The post you are reading will summarize some related true-crime cases, particularly the kidnap and murder of Charles Lindbergh, Jr.  As mentioned in the previous post, the setting of a railway train is particularly evocative for a mystery.  To date, no single crime has comprised all the elements from the novel, but there have been several noteworthy cases involving trains since its publication.

Maria Farcasanu

In 1935, shortly after Murder on the Orient Express was published, the body of a Romanian fashion designer named Maria Farcasanu was found near the tracks of the Orient Express in Admont, Austria.  She had been traveling from Bucharest to Paris, and her purse was discovered 5 km from the body.  Her husband stated she would have been wearing a silver fox fur stole that was not found with the body.  Although the death may have looked like a suicide or accident initially, these facts led the police to suspect foul play.

Three days following the discovery of the body, Farcasanu’s baggage was located in a check room in Basel, Switzerland, and all items of value had been removed.  Police originally suspected Trajan Theodorescu, a swindler who targeted female Orient Express passengers, but he had an alibi during Farcasanu’s trip.  Pawn brokers were asked to be on the lookout for the fox fur stole and a pricey wristwatch missing from her baggage.

Maria Farcasanu
Maria Farcasanu

Some time later, a Swiss detective name Karl Nievergelt noted a fur piece worn by a Sunday morning churchgoer.  She stated it was a gift from her Hungarian student boarder, Karl Strasser.  Strasser was arrested shortly thereafter and confessed to committing the crime for financial gain.  Initially sentenced to death, Strasser’s fate was commuted to life in prison in 1937.

Two Unsolved Cases

Within the year after the publication of Murder on the Orient Express, a man’s body was discovered in a passenger car of a train as it entered a station in Cincinnatti, Ohio.  A pair of shoes next to the body that did not belong to the man was the only clue to his mysterious death, and the crime was never solved.

In The Life and Crimes of Agatha Christie, Charles Osborne recounts the following:

On 3 May 1981, the London News of the World reported a murder in Bamberg, West Germany, which it called ‘a carbon-copy crime of Agatha Christie’s thriller, Murder on the Orient Express’.  The method by which a sixteen-year-old girl was killed certainly suggested a knowledge of the novel or the film.

Unfortunately, this writer has been unable to locate additional information about this tantalizing case and encourages the reader to make contact if he or she can provide any details.

The Big One

Undoubtedly, the most notable true-crime case associated with Murder on the Orient Express is the one that inspired it: the kidnapping and murder of the Lindbergh baby, Charles Lindbergh, Jr.  In what may be the actual Crime of the Century, the 20-month-old son of the famous aviator Charles Lindbergh and Anne Morrow (daughter of Ambassador Dwight Morrow) was kidnapped from his nursery on the evening of 01 Mar 1932.  A ransom note was found on the radiator below the window of the room and demanded $50,000 for the safe return of the baby.

Anne and Charles Lindbergh (Hulton Archive/Getty Images)

At the time of the kidnapping, Anne Morrow was 7 months’ pregnant with her second child, which Christie paralleled with Sonia Armstrong in Murder on the Orient Express.

The nation erupted.  Charles Lindbergh was one of the most famous and highly regarded individuals at the time, having been the first aviator to cross the Atlantic Ocean in 1927.  After the kidnapping, a popular song posed the questions:

Who stole the Lindbergh baby?
Was it you? Was it you?
After he crossed the ocean wide,
Was that the way to show our pride?
Was it you? Was it you? Was it you?

 Despite the Lindberghs paying the ransom, the body of young Charles Lindbergh, Jr., was found on 12 May 1932.  The extent of decomposition of the body suggested he was murdered very shortly after being kidnapped.  During autopsy, the cause of death was concluded to be “fractured skull due to external violence,” but it was never known if this violence was accidental or intentional.

Original poster circulated following the Lindbergh baby kidnapping

Prior to the Lindbergh case, kidnapping was not a federal crime.  After the kidnapping of the Lindbergh baby, the US Congress passed the Lindbergh Law, which made it one.

An Inside Job?

An early theory of the police was that the kidnapping was an inside job.  The Lindberghs had begun construction on an estate in Sourland, New Jersey in 1930.  By 1932, the Lindberghs lived with Anne’s parents in Englewood, New Jersey, but spent weekends at the Sourland property.  However, the family happened to be staying at Sourland the Tuesday night of the kidnapping.  Police surmised that an inside source such as a member of the household staff may have inadvertently betrayed this to or were deliberately colluding with the kidnappers.

The police centered some of their investigation on Violet Sharp, a 28-year-old English maid.  The staff had informed the police that Sharp had a date with an unknown man on 28 Feb.  When she was interviewed on 10 Mar, the police reported Sharp was evasive and could recount no details of the man or the date.  Additionally, Sharp’s sister, Emily, returned to England shortly after the ransom money had been paid without notifying the police of her travel plans.

Sharp was interviewed 3 more times, with each subsequent interview increasingly more invasive.  The police interrogated Sharp regarding her relationships with men so forcefully that the fourth interview was cut short by an attending physician due to Sharp’s rapid pulse and high blood pressure.  The following day, the investigators returned for a final attempt to speak with Sharp.  Sharp refused to be interviewed and retreated to her bedroom with a measuring glass filled with powdered silver polish.  In her desperation, she drank the polish (cyanide chloride) and died a short time later.

A total of 18 characters in 14 of Christie’s stories and novels died from cyanide poisoning.

To date, there has been no direct evidence linking Violet Sharp to the kidnapping and murder of Charles Lindbergh, Jr.  Her travails are mirrored by the character of Susanne Michel (daughter to Pierre Michel) in Murder on the Orient Express.

Countess Andreyni (sister to Sonia Armstrong) recounted:

Poor Susanne? Yes, I had forgotten about her. The police questioned her. They were convinced she had something to do with it. Perhaps she had—but if so, only innocently. She had, I believe, chatted idly with someone, giving information as to the time of Daisy’s outings. The poor thing got terribly wrought up—she thought she was being held responsible.” She shuddered. “She threw herself out of the window. Oh it was horrible.”

Notably, Christie’s characters most directly based on individuals involved in the Lindbergh kidnapping (Susanne Michel and John, Sonia, and Daisy Armstrong) were only referenced by characters in Murder on the Orient Express and not active participants in the plot.  This may have been done by Christie out of respect for the Lindbergh family.

A Promising Lead

Although the police devoted time and resources to characterizing Violet Sharp’s romantic relationships, the most valuable clues were uncovered immediately during their investigation: the ransom note and a hand-made ladder, custom built to reach the window to Lindbergh’s nursery.  Police suspected that the ransom note left on the radiator was written by someone from Germany, given the placement of the dollar signs and the grammatical construction.

Lindbergh baby kidnap ransom note
Ransom note left in the window of Charles Lindbergh, Jr

This note and the subsequent ransom notes were helpful to secure a conviction for one kidnapper, but the smoking gun in this case was the ladder found about 70 feet from the Lindbergh estate.  

The examination of the ladder using forensic xylotomy, the tracing of the ransom money, and the conclusion of the Lindbergh case will be the focus of the next blog post.