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

  Conan Doyle published a lengthy pamphlet on the case, which led to the partial exoneration of the beleaguered solicitor. The charge of animal mutilation was dismissed, but the charge of having written the letters stood. There are cynical souls who believe this was due to the influence of Sir Albert de Rutzen, one of the three members of the commission deciding the matter. By an uncanny coincidence, he was the cousin of the chief constable of the Great Wyrley Police. Conan Doyle remarked that he was never able to think back on this case without anger.

  The crime scenes in the Edalji case were largely exterior, involving fields, grass, and varieties of soil. Interpreting them properly required a good knowledge of natural science. Interior crime scenes presented a different set of difficulties and often required an understanding of architecture and interior decoration.

  One problem of interior crime scene investigation addressed by both Sherlock Holmes and Dr. Hans Gross was determining whether one had, in fact, located the entire crime scene. The existence of secret rooms, trap doors, and hidden evidence needed to be considered.

  Gross insisted that absolutely everything needed to be examined, and he mentioned some of the peculiar hiding places in which evidence had been found: a birdcage, a clock, a prayer book, even a pot of boiling soup that was found to contain missing gold pieces. Walls must be tapped on to uncover a hollow sound, which might indicate a cavity.

  Floors were a problem, as they were hard to remove entirely. Gross suggested examining the nails holding the floorboards. He noted that these would show signs of rust if they had been there for a long time. If the wood around the nails showed signs of bruising, it was an indication that something had been hidden there. In the case of an earthen floor, water was to be poured over it; the place where bubbles appear and where the water filters through rapidly indicates an area where the floor has been recently disturbed.

  In the nineteenth century, secret passageways and hidden rooms were a more frequent part of private houses than they are today. As there was no central heating, homes of the period were constructed with thick walls to provide insulation. These accommodated discreet space for hollows in which to store things. Even modest middle-class households made their homes accessible to a wide variety of hired help—chimneys needed to be swept, laundry to be washed. It was comforting to be able to hide valuables from strangers. In some very old houses, elaborately disguised rooms, often referred to as “priest’s holes,” had been constructed to hide fugitive adherents of out-of-favor religions.

  All of these architectural oddities provided happy inspiration for criminals, detectives, and writers of fiction. In “The Adventure of the Speckled Band,” Holmes, carefully inspecting the victim’s room, quickly focuses on an inconsistent detail that indicates that the crime scene must include the neighboring room:

  “Very strange!” muttered Holmes, pulling at the rope. “There are one or two very singular points about this room. For example, what a fool a builder must be to open a ventilator into another room, when, with the same trouble, he might have communicated with the outside air!”

  And, of course, the ventilator was used by a murderous serpent. Harry Söderman, the famous Swedish forensic scientist, writ

  ing his memoirs in the twentieth century, described a crime scene

  with a similar zoological detail. In New York City during the

  1930s, police were certain that a merchant was selling small packages of opium from his apartment, but they had no idea where he

  stored the drug. The merchant had a pet ferret of which he

  seemed very fond, as it sat on his lap and fed from his hand. The detectives stationed themselves outside the apartment

  and watched through the window. They saw what they believed to

  be a customer arrive and give money to the merchant, who whispered to the ferret. The animal promptly disappeared under the

  sink, returning a few seconds later with a packet in his mouth.

  The ferret was rewarded with a bit of raw meat. As the customer

  left with the packet, he was stopped and searched. The packet he

  carried contained opium.

  A complete examination of the premises disclosed an opening

  below the sink that was too small for human access. The police

  enlarged it and found thirty-nine packets of opium neatly lined

  up. Evidently, Söderman surmised, they had been arranged by the

  tidy but felonious ferret.

  Sherlock Holmes locates hidden rooms by careful measurement as well as by observing inconsistent design. In “The Adventure of the Norwood Builder,” knowing that the scheming villain is a builder, Holmes suspects that the man has altered his house to provide a hiding place and thus is able to determine the man’s whereabouts: “When I paced one corridor and found it six feet shorter than the corresponding one below, it was pretty clear

  where he was.”

  In “The Adventure of the Golden PinceNez,” Holmes

  locates a hidden assailant by a combination of attention to detail

  and a knowledge of the frequent use of bookcases to conceal hidden rooms:

  “I examined the room narrowly for anything in the shape of a hiding-place. The carpet seemed continuous and firmly nailed, so I dismissed the idea of a trap-door. There might well be a recess behind the books. As you are aware, such devices are common in old libraries. I observed that books were piled on the floor at all other points, but that one bookcase was left clear. This, then, might be the door.”

  And, of course, it is indeed the door.

  It is a pity that Sherlock Holmes’s techniques were not promptly utilized in 1992 when Katie Beers, just short of her tenth birthday, disappeared on December 28 in Bay Shore, Long Island, while on an outing with John Esposito, a family friend. Police had immediate suspicions of the middle-aged Esposito, but he denied all knowledge of where the child might be. A search of his home disclosed nothing that seemed unusual.

  He was followed constantly and interrogated repeatedly. Finally, on January 13, 1993, pressured by questioning beyond his endurance, Esposito confessed that he had kidnapped Katie and had been holding her captive. He directed the police to the place where he had hidden her. She was found, fortunately still alive, in the grim, secret room that Esposito had constructed under his house. As in “The Adventure of the Golden PinceNez,” the entrance to it was concealed behind a bookcase.

  Much like the title character in “The Adventure of the Norwood Builder,” John Esposito was a contractor. Those who searched for Katie, unlike the clever chap in Conan Doyle’s The Sign of Four, had not “worked out all the cubic space of the house, and made measurements everywhere, so that not one inch should be unaccounted for.”

  Hans Gross wrote in his Criminal Investigation regarding the proper examination of a crime scene:

  In no other duty are power of observation, logical reasoning, and keeping the purpose in view so clearly revealed; and nowhere else can more striking examples of disorder, feebleness of observation, vagueness, and hesitation be found.

  “You know my method. It is founded upon the observation of trifles,” Holmes said in “The Boscombe Valley Mystery.” As Gross would have agreed, it is the observation of “trifles” at a crime scene that is the heart of forensic science.

  Whatever remains

  • In 1916, at Berkley, California, Dr. Albert Schneider, a chemist, eager to gather and retain every possible scrap of evidence from a crime scene, realized that the household vacuum cleaner, which had been patented in 1901, was the perfect device for collecting dust particles. He published a paper explaining his method in the journal Police Microscopy.

  • Animals, wild or domesticated, roaming loose at a crime scene often devour or otherwise disarrange vital evidence. When O. J. Simpson’s estranged wife, Nicole, and her friend, Ron Goldman, were stabbed to death in June 1994, a large dog was present at the scene. The canine witness, an Akita, was briefly evaluated by a K9 handler but was retu
rned to the Simpson family by the police. As veterinarians and distressed owners will attest, dogs sometimes swallow large and surprising objects, including knives. The Simpson Akita was not x-rayed, nor was his fecal matter collected or examined. This may have been a mistake, as the murder weapon remains unaccounted for.

  • When a victim’s body has been moved from the homicide location, the crime scene to be investigated includes the disposal spot, as well as the route and vehicle used to reach it.

  CHAPTER 7

  A Picture of Guilt

  “You are aware that no two thumb-marks are alike?” —Inspector Lestrade in “The Adventure of the Norwood Builder”

  Sherlock holmes dedicates much of his time to identifying the perpetrators of complex crimes. Sometimes, as in The Valley of Fear, he must uncover the identity of the victim as well. Holmes, of course, could accomplish this with practiced panache. As he remarks in A Study in Scarlet, referring to a Gallic fictional detective (who was no doubt modeled by his creator, the French novelist Emile Gaboriau, after the famous Vidocq):

  “Lecoq was a miserable bungler; he had only one thing to recommend him, and that was his energy. That book made me positively ill. The question was how to identify an unknown prisoner. I could have done it in twenty-four hours. Lecoq took six months or so. It might be made a textbook for detectives to teach them what to avoid.”

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  Sherlock Holmes, of course, had the easy confidence of a man who not only possessed very special talents but who also practiced detection with the adroit help of Conan Doyle. In the more plebian real world, accurate identification of individuals had always been a recalcitrant conundrum that complicated criminal investigation, and it wasn’t until the nineteenth century that scientific solutions to this problem began to be utilized. But as the field developed, the Sherlock Holmes stories provided effective advertisement for the new ideas.

  Since multiple convictions evoked greater penalties and in some cases death sentences, the authorities were at pains to determine the criminal history of prisoners. The earliest method of identifying criminals was by physically marking them. Mutilation by court order was a lucrative sideline of executioners on the European continent, who charged extra for branding, nose cutting, and the occasional amputation.

  Branding was abandoned in France under the revolution (with the guillotine so busy, there may have been a shortage of enough surviving subjects to wear the brand), but the penalty was revived later. It was finally abolished in 1832. The Swedish criminalist Harry Söderman noted in his memoirs that in France prisoners not sentenced to death were marked TF for “travaux forcés” (hard labor); a V stood for “voleur” or thief, with a second V added for a second conviction. A life sentence was indicated by the letter P, which stood for the ominous “en perpétuité.”

  In Russia, well into the mid-nineteenth century, the faces of prisoners were commonly branded—one large letter burned upon the forehead, accompanied by one on each cheek.

  While one would expect convicts to hide their identities, some, perhaps driven by a need to flirt with disaster, would mark themselves with painfully acquired tattoos. These too provided a convenient source of identification for the authorities. Both the nineteenthcentury pathologist Alexandre Lacassagne and the Italian criminologist and anthropologist Cesare Lombroso collected notes on the variety of tattoos favored by criminals. In his paper “The Savage Origin of Tattooing,” published in the April 1896 edition of Popular Science Monthly, Lombroso wrote of an assassin named Malassen who had ultimately followed a second career path as an executioner. Malassen flaunted a red and black guillotine on his chest, accessorized by an inscription in red letters: “J’ai mal commencé, je finirai mal. C’est la fin qui m’attend” (I began evil, I shall end evil. That is the end that awaits me). His right arm, with which he had dispatched a number of his criminal former colleagues, bore the legend “Mort à la chiourme” (Death to the convict).

  Lombroso also quoted from Lacassagne’s collection of other such spirited messages. They ranged from the self-pitying “Son of misfortune,” “Born under an evil star,” “The present torments me; the future frightens me,” and “No chance” to the threatening “Death to unfaithful women!” and “Vengeance!” to the cheerfully patriotic and gustatory “Vive la France and fried potatoes!”

  Lombroso, firmly convinced that tattooing was a sign of atavism, criminality, and insensitivity to pain, was appalled to discover his theory somewhat shaken by a fad for tattooing among the upper classes in Victorian London, embraced especially by the ladies. Even Lady Randolph Churchill (the former Jenny Jerome and the mother of Winston) wore a delicately designed snake encircling her wrist. (She hid it discreetly under a bracelet on formal occasions.)

  Lombroso might have been shocked, but Sherlock Holmes, as an expert on tattoos, would have found Lady Churchill’s ornament intriguing and would no doubt have been able to determine at a glance the origin of the design. He demonstrates his knowledge in “The Red Headed League” when he says to a client:

  “The fish that you have tattooed immediately above your right wrist could only have been done in China. I have made a small study of tattoo marks and have even contributed to the literature of the subject. That trick of staining the fishes’ scales of a delicate pink is quite peculiar to China.”

  A good knowledge of tattoos and scars was most useful to a Victorian-era detective. The English police of the period maintained a tattoo index that listed designs popular among criminals. The forensic pathologist Charles Meymott Tidy devoted pages in his 1882 textbook, Legal Medicine, to the formation and appearance of “Cicatrices [scars] and Tattoo Marks” and included exhaustive instructions on how to differentiate between them. Clearly, Conan Doyle was well aware of the issue, as he has the local doctor observe in The Valley of Fear:

  The dead man’s right arm was thrust out from his dressing gown, and exposed as high as the elbow. About halfway up the forearm was a curious brown design, a triangle inside a circle, standing out in vivid relief upon the lard-colored skin.

  “It’s not tattooed,” said the doctor, peering through his glasses. “I never saw anything like it. The man has been branded at some time as they brand cattle.”

  Both scars and tattoos figured heavily as evidence in the famous identity case of the Tichborne Claimant in 1866, which had riveted England and much of the rest of the world for eight years. Holmes, whose knowledge of old cases is described as prodigious, would certainly have been familiar with it.

  Sir Roger Tichborne, the unmarried heir to a baronetcy and the vast Tichborne estate, was twenty-five years old when he was reported lost at sea off the coast of Brazil in 1854. His French mother, who had raised him in her native land and language until he was sixteen, refused to accept his loss.

  In 1866, a man from Wagga Wagga, Australia, who had been living under the name of Castro, claimed to be the lost heir. He explained that having made his way to Australia after surviving the sea disaster, he determined to make a success on his own before returning to England. Unable to succeed, he had been too embarrassed to contact his relations, but seeing an advertisement for his whereabouts on behalf of his dear mother, he’d been full of remorse and desired to travel to Europe to establish his identity. He needed passage money for himself. And his wife. And his children. Lady Tichborne sent it at once. The Castro family set sail for Europe.

  When last seen, Roger Tichborne had been very thin and possessed a narrow, gracile frame. He was, of course, fluent in French, which had been his first language. The man who presented himself was enormously obese and spoke no French at all, explaining that he had somehow forgotten it during his sojourn in Australia. The given names of Lady Tichborne (Henriette Félicité), whom he claimed as his mother, had also unfortunately slipped his mind. (Happily, he did recall the name of the family dog.) Full of hopeful anticipation, Lady Tichborne insisted on seeing the gentleman for herself.

  Carefully surveying the bulky body and heavily jowled face of the C
laimant, she joyfully proclaimed that he was indeed her son, proving that the eye sometimes sees only what the heart desires. She proceeded to grant him an allowance of a thousand pounds a year.

  The lady may have chosen to ignore the physical differences between her lost son and the Claimant, but it was impossible for many other members of the family to agree. The physical factors included extensive tattoo marks that had been inscribed on Roger’s arm. These were remembered, described in detail, and sketched by a number of friends and relations. There were no tattoos on the Claimant. The Claimant had a birthmark on his side, but there had been no such mark on Roger, who had been bled many times for a variety of illnesses, as was common in that era. These procedures had left scars. They were not present on the Claimant.

  There were a number of other inconsistencies, not the least of which was that Roger’s eyes had been blue and the Claimant’s were brown. The noses and the ears of the two men were of different shapes. The Claimant was taller by an inch. You might think these facts would have given Lady Tichborne pause, but she remained adamant that her son had miraculously been restored to her and with mulish stubbornness continued to maintain that position until her sudden death of heart failure in 1868.

  With her demise, the Claimant’s allowance stopped and his legal troubles began. The many other members of the Tichborne family who had refused to accept the gentleman from Wagga Wagga as the heir to the estate were obdurate. As a result, the English judicial system was called upon to settle the issue. This was much to the advantage of many members of the legal profession, whose exchequers grew plump on the proceedings. A vast amount of newsprint was spent on the case, much of it hyperbole. The public, unwilling to be restrained by lack of accurate information, took passionate sides.

  There were debates in Parliament. Benjamin Disraeli, the prime minister, although convinced that the Claimant was an imposter, allowed petitions on his behalf to be read in Commons in the interests of fairness and keeping the peace. After four years and two well-attended trials (even the prince and princess of Wales made an appearance), the Claimant was found guilty of imposture and sentenced to fourteen years of penal servitude. He served ten years of his sentence, leaving prison a sadder, wiser, and much thinner man. The case stood as a testament to the unreasoning force of wishful thinking, the unreliability of eyewitness testimony, and the serious need for a scientific method of objectively establishing physical identification.