The Science of Sherlock Holmes: From Baskerville Hall to the Valley of Fear, the Real Forensics Behind the Great Detective's Greatest Cases

by E. J. Wagner

  Ballistics research was spotty and uncoordinated. As there was no consensus as to which branch of science the subject belonged to, different specialties dabbled in it from time to time. Pathology made an early attempt when, in 1889, Professor Alexandre Lacassagne noticed the distinctive striations on a bullet he removed from a murder victim. Examining the revolvers of a number of suspects, he matched the bullet’s seven grooves to one of the guns. But Lacassagne studied only the weapons shown to him by the police. If the bullet had come from a different gun, his conclusion would be incorrect. Lacassagne was evidently able to live with the ambiguity, but the unfortunate owner of the revolver, who was convicted of murder, was not.

  Jürgen Thorwald, in his Century of the Detective, provides an account of a contribution made by the famous German chemist Paul Jeserich in 1898. Dr. Jeserich was asked to determine whether the bullet removed from a murder victim had come from the gun owned by the defendant. He proceeded by firing a test bullet from the suspect’s gun and then taking microphotographs of both the test bullet and the murder bullet. Comparing the pictures, he observed small defects in the markings of the lands and grooves on both bullets that he believed were unusual and that matched each other.

  Although Jeserich had little experience with firearms, and, like Lacassagne, had examined only the gun given to him by the police, he gave solid testimony for the prosecution. The chemist had only a moderate interest in ballistics and did not actively pursue the subject further. But the defendant, convicted on Jeserich’s testimony of a capital crime, no doubt found the subject worthy of thought as he faced his death sentence.

  In 1913, Victor Balthazard, a noted French expert in medical jurisprudence, published a paper in the Archives of Criminal Anthropology and Legal Medicine. His research established that every fired bullet shows a variety of distinguishing marks influenced by many parts of the firearm. Therefore, Professor Balthazard argued, each bullet has its own fingerprint and is unique.

  This conclusion was theoretically fascinating, but in 1913 the world was trembling on the starting edge of the Great War. Research into single murders seemed unimportant and had to take a back seat to the manufacture of engines of mass death.

  Sir Sydney Smith, the eminent British forensic pathologist and a great admirer of Sherlock Holmes, noted in his 1959 memoir, Mostly Murder, that in 1919 little progress had been made in the field of ballistics since the days of Henry Goddard. “As far as I was concerned,” Sir Sydney wrote, “it was still a virgin field.” Maintaining that bullets were the concern of the pathologist, since the damage they do to the human body is obviously a medical issue, he proceeded to devote himself to the subject. He had been appointed the principal medicolegal expert in Egypt in 1917, and since murder by gunshot was regularly practiced in that time and place, he had ample opportunity to study it.

  The invention of the comparison microscope in 1923 made it possible as never before to evaluate the patterns on two bullets simultaneously in greatly enlarged detail, reducing the chance of error. Sir Sydney made prompt use of this microscope. He published a highly successful textbook in 1925, and his research on ballistic evidence was very influential in the English-speaking world.

  But even Sydney Smith’s expertise would not prevent the judicial debacle that occurred in Edinburgh, Scotland, in 1926, when a fifty-six-yearold lady named Bertha Merrett, quietly writing a letter in her sitting room, suffered a nasty encounter with a pistol. Mrs. Merrett was an Englishwoman of the upper middle class who had spent much of her married life abroad with her engineer husband. She had followed him diligently wherever his professional interests led him, from New Zealand to St. Petersburg, Russia. But their only child, a son named John Donald, was somewhat delicate. The severe climate of Russia eventually stressed the child’s health, and his mother took him to Switzerland to recover, thus missing the excitement of both the Great War and the Russian Revolution. Her husband, who had remained behind, disappeared in the maelstrom.

  By 1924, when the boy was sixteen, Mrs. Merrett had brought him to the British Isles to complete his education. In 1926 (which was to prove the Merrett annus horribilis), they were living in a modest flat in Edinburgh, and John was enrolled at Edinburgh University, a nonresident school. They had acquired the regular services of a maid who came in each morning.

  According to all accounts, Bertha Merrett was a woman of great intelligence with a fine eye for business and total devotion to her son. John Donald Merrett had a quick mind, charming manners, and good looks, but he balanced these fine qualities with an impressive degree of self-absorption. Careful not to strain his academic ability by excessive study, he avoided actually attending class whenever possible. He kept this from his credulous mother, just as he kept from her the fact that he spent his pocket money on gambling, drinking, and ladies of the evening.

  On March 17, 1926, the maid arrived at 9 A.M. as usual and greeted mother and son, who seemed in ordinary cheerful spirits. Mrs. Merrett was writing letters, and her son was reading on the opposite side of the room. The maid was in the kitchen when she heard the sound of a pistol shot, a scream, and a thud. Young Merrett entered the kitchen and said, “Rita, my mother has shot herself!”

  In the sitting room, the appalled maid saw Mrs. Merrett lying supine on the floor, still alive, but bleeding profusely from a head wound. A pistol lay on the bureau a few feet away.

  Two constables, the memorably named Middlemiss and Izatt, responded to the scene, but instead of being content to merely conduct a methodical investigation, they vigorously set about creating a disturbance. They moved furniture, papers, and books with abandon while diagramming nothing. They did manage to note John Donald’s statement that his mother had suddenly shot herself as she was writing letters because “she was worried about money matters” and that he had purchased the gun to “shoot rabbits.” They ignored the letter the lady had been in the process of writing and the fact that it was a simple, amiable letter to a friend that contained no suicidal overtones. The police assault on the scene reached its apogee when one officer picked up the weapon and stuffed it in his pocket without recording where he had found it.

  Mrs. Merrett, still breathing but unconscious, was removed to the infirmary, where she was placed in the locked ward with barred windows where those who had attempted the criminal offense of suicide were confined. She regained consciousness and complained of a terrible pain in her right ear. This was quite understandable, as an x-ray had disclosed a bullet in the base of her skull. The location of the wound made it inoperable. The patient was told only that she had had a “little accident,” as it was considered unwise to alarm her.

  Unprompted, she told hospital personnel and friends repeatedly that she had been calmly writing letters, that her son had stood too close to her, that she had told him, “Go away, Donald, and don’t annoy me,” and that she had heard a sudden bang in her head, “like a pistol.” She had no memory of a pistol being in the house. So unaware was Mrs. Merrett of the true nature of her injury that she asked a friend to arrange a consultation with an ear specialist. At one point, she said with admirable maternal forbearance, “Did Donald do this? He’s such a naughty boy.” None of this information was recorded by police investigators.

  Young Merrett, evidently too exhausted by filial concern to visit the hospital regularly, inquired of the doctor, “Is it in the cards that she might recover?” The answer soon came. On April 2, Bertha Merrett’s obituary appeared in the Scotsman. John Donald Merrett was now officially due the sympathy given to an orphan.

  A postmortem was performed by Professor Harvey Littlejohn, who was both chair of forensic medicine at Edinburgh and a former teacher of Sydney Smith. The immediate cause of death was determined to have been basal meningitis, the result of the infection of a bullet wound. Littlejohn’s report included the words:

  There was nothing to indicate the distance at which the discharge of the weapon took place, whether from a few inches or a greater distance. So far as the position of the wou
nd is concerned, the case is consistent with suicide. But Bertha Merrett’s family and friends were insistent that suicide would have been abhorrent to her. There had been nothing in her demeanor prior to the shooting that indicated depression. Her statements in the hospital supported their view. Further, selfinflicted gunshots are unusual in females (although not unheard of), and the angle of the wound at the back of the head seemed awkward. The discovery by the bank that the young orphan had been embellishing his pocketbook by forging his mother’s name appeared suggestive.

  Littlejohn, reconsidering, and aware of his former student’s expertise with gunshot wounds, asked for the opinion of Sydney Smith. Sir Sydney, going over the evidence, noted that the doctors at the infirmary had observed the lack of tattooing, or powder marks, around the bullet wound. The question was, he felt, would the weapon that made the wound leave such marks if discharged close enough to the head as to indicate suicide.

  He suggested that Littlejohn experiment with the weapon that shot Bertha Merrett. Littlejohn procured the gun, which was a six-cartridge .25 Spanish automatic, loading it with the same type of ammunition used in the Merrett shooting. He fired it at a number of targets, including one made of the skin of a recently amputated leg. He measured the distance each time and discovered that at three inches or less, very obvious powder and burn marks appeared on the target. Marks appeared at six inches. These marks were not only evident to the naked eye, they were exceedingly difficult to remove. It took a distance of nine inches before no marks appeared, and certainly no one could shoot themselves behind the ear at such a long range. (The importance of powder marks was well known to Sherlock Holmes, who says in “The Reigate Squires”: “The wound upon the dead man was, as I was able to determine with absolute confidence, fired from a revolver at the distance of something over four yards. There was no powder-blackening on the clothes. Evidently, therefore, Alec Cunningham had lied when he said that the two men were struggling when the shot was fired.”)

  Littlejohn, to his great credit, wrote a new report, stating that accident was “inconceivable, suicide in the highest degree improbable,” and that the circumstances “pointed to homicide.”

  John Donald Merrett now received the rapt attention of the Scottish judicial system and was indicted on charges of both murder and forgery. Littlejohn, of course, would testify for the Crown. A guilty verdict seemed inevitable. And then Merrett’s attorney made an amazing announcement. The expert witness for the defense would be Sir Bernard Spilsbury.

  Sir Bernard, the English Home Office pathologist, had a sterling reputation as a brilliant expert on homicide in general and shooting cases in particular. His fame, since his early foray into the public’s awareness during the Crippen case, had grown enormous, and his ability to impress a jury was formidable. His official position meant that in England he usually appeared for the Crown, so his appearance in Scotland on the side of the defense was startling. Further, Sir Bernard shared the burden of the defense evidence with Robert Churchill, a wellknown gunsmith who frequently collaborated with Spilsbury on shooting cases.

  They firmly stated their belief that Bertha Merrett had committed suicide and that the absence of powder burns or tattooing was unimportant. They testified that they had carried out repeated experiments that showed that powder marks need not have been left around the wound even if the shot was at close range.

  The problem was that the weapon and ammunition they had experimented with were entirely different from the gun and bullets that had killed Bertha Merrett. Spilsbury and Churchill stubbornly refused to reconsider their position in spite of intense cross-examination. Regardless of the superiority of Littlejohn’s experiments, the fact that he had changed his opinion suggested a weakness of his position to the jury. The impact of Spilsbury’s determined testimony and the sloppiness of the police investigation all aided the aggressive defense.

  After deliberations that lasted for one hour and five minutes, the jury returned. On the charge of murder, they announced the equivocal Scottish verdict: “Not proven.” On the charge of forgery, Merrett was found guilty. Sentence of imprisonment for one year was pronounced by the lord justice-clerk.

  Sir Sydney Smith, hearing of the verdict, famously remarked, “That’s not the last we’ll hear of young Merrett.” Unfortunately, he was right.

  John Donald Merrett served his sentence in a low-security institution. Officially guilty of no capital crime, he was able to inherit from both his mother’s estate and his grandfather’s. He married young, and to please his wife, he settled a large sum of his inheritance on her. Tiring of her after a while, he casually abandoned the lady. He spent the ensuing ten years in smuggling, gunrunning, drug dealing, and other creative enterprises. He served in the British Navy during World War II, under the name Ronald Chesney. He served well, as far as is known.

  By 1954, Merrett/Chesney was living in Germany with his mistress when he noticed he was short of funds. He recalled having given the woman to whom he was still legally wed a sum of money. She strongly preferred not to return it.

  Merrett/Chesney concluded that strong measures were needed. He took a boat to England, stole a passport from a man in a pub, and returned to Germany, making certain that his departure from the British port was noticed. He then returned to England with the stolen passport and entered the house where his cast-off spouse lived. He drowned her in the bath, where he left her corpse, intending for her death to appear an accident. His plan was spoiled when, as he left, he met his mother-in-law on the stairs. He promptly and violently dispatched the inconvenient lady, thereby destroying any hope that he might appear to have been widowed by accident.

  He raced back to Germany, but the police, sharper than they had been in 1926, were on his trail. Knowing that arrest was inevitable, Merrett (perhaps thinking of Mother) shot himself in the head.

  There are few figures as dangerous as that of an expert witness who is brilliant, persuasive, famous, obstinate, and absolutely mistaken. Sir Bernard Spilsbury and Robert Churchill had between them made possible the murder of two harmless women.

  In “The Yellow Face,” Sherlock Holmes, acknowledging a rare error, says:

  “Watson, if it should ever strike you that I am getting a little over-confident in my powers, or giving less pains to a case than it deserves, kindly whisper ‘Norbury’ in my ear, and I shall be infinitely obliged to you.”

  Someone needed to say the equivalent of “Norbury” to Sir Bernard.

  Whatever remains

  • There are many accounts, in a number of languages, of the Henry Goddard case, that claim that the crime solved by the bullet mold was a murder. Goddard’s book, Memoirs of a Bow Street Runner, make it very clear that this is not accurate.

  • The Merrett case was mishandled, but the publicity it generated provided the catalyst for the further study of ballistics. The field developed rapidly in the period after the last Holmes stories were published in 1927. At the present time, the analysis of ballistic evidence is for the most part divided into three specialized areas:

  Interior ballistics: how the bullet moves within the firearm after it is fired.

  Exterior ballistics: how the bullet moves after it leaves the barrel.

  Terminal ballistics: the effect of the bullet on the object it strikes.

  • In the story “The Problem of Thor Bridge,” Sherlock Holmes proves that a gunshot death is a suicide staged as a murder. As Leslie S. Klinger, the noted Holmes scholar, recounts in his The New Annotated Sherlock Holmes, there are striking similarities between the plot of “The Problem of Thor Bridge” and a case described by Hans Gross in his Handbook for Criminal Investigation. Suicide deliberately dressed as murder is seen by crime investigators from time to time. The usual motives are to ensure that the next of kin receive insurance payments, as in the Gross case, or to frame and so punish an enemy, as in “The Problem of Thor Bridge.”

  CHAPTER 9

  Bad Impressions

  “There has been murder done, and the m
urderer was a man. He was more than six feet high, was in the prime of life, had small feet for his height, wore coarse, square-toed boots and smoked a Trichinopoly cigar.”

  —Sherlock Holmes in A Study in Scarlet

  Sherlock holmes is a walking repository of eclectic information. All sorts of arcane tidbits interest him, but he holds nothing of greater importance than the study of footprints. In the novel A Study in Scarlet he observes, “There is no branch of detective science which is so important and so much neglected as the art of tracing footsteps. Happily, I have always laid great stress upon it, and much practice has made it second nature to me.”

  The study of footprints was one of the first tools of forensic science. (In his Memoirs, Vidocq mentions recording footprints, although he doesn’t discuss their use in detail.) The identification and tracing of track marks were part of humankind’s repertoire since we first learned to hunt both four-footed animals and each other. It was only natural that this skill be adopted by the new field of criminal science, and it was vigorously if primitively exercised by

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  the Glasgow police during their investigation of the famously bizarre murder of Jessie M’pherson in 1862.

  On Monday, July 7 of that year, John Fleming, a respectable accountant of middle age, returned with his son from a weekend in the country to his home at number 17 Sandyford Place in Glasgow. He found his father, James Fleming, who shared the residence, alone and unable to explain the apparent absence of Jessie M’pherson, the servant girl who looked after him. Old Fleming said he hadn’t seen her all weekend.