He’s come to be referenced as a historical figure rather than a fictional one (often at the expense of his actual author), with countless legends surrounding him. Perhaps the most popular is that he invented modern forensic science.
In his very first story, 1887’s “A Study in Scarlet,” Doyle
describes Holmes as “well up in anatomy, and … a first-class chemist,” who “has never taken out any systematic medical classes” but has nonetheless “amassed a lot of … knowledge which would astonish his professors.” Holmes didn’t have official forensic training simply because there was none; the
first forensic science program was established at the University of Lausanne, Switzerland, in 1909.
Where Holmes did get his prodigious medical knowledge was from his creator. Doyle
was a practicing ophthalmologist who wrote as a hobby, much like Holmes’ partner and chronicler, Dr. Watson.
Holmes is also based on a real physician,
Dr. Joseph Bell, a
mentor of Doyle’s at the University of Edinburgh, who had even
assisted police in murder investigations. In 1892, Doyle
wrote to Bell: “It is most certainly to you that I owe Sherlock Holmes … I do not think that his analytical work is in the least an exaggeration of some effects which I have seen you produce in the out patient ward.”
At a time when solving crimes mostly consisted of collecting eyewitness accounts and rounding up the usual suspects (often to coerce a confession), Doyle imported the
methodical examination and evidence-based deduction of medicine to police work.
Holmes didn’t invent the idea of using science to solve crimes, but
he did popularize it.
Holmes’ magnifying glass
Of the various forensic techniques attributed to Holmes, the most famous is
the use of a magnifying glass. It’s as much a part of his iconic image as the deerstalker cap and calabash pipe.
It’s first mentioned in “A Study in Scarlet,” which does mark
the first time a magnifying glass is used in a work of fiction to examine a crime scene, even though magnifying glasses in different forms
had been around for centuries.
It’s unclear whether magnifying glasses were used in investigative fieldwork before then, but Sir Sydney Smith (1883-1969), professor of forensic medicine and dean of medicine at the University of Edinburgh and one of the world’s preeminent forensic experts,
credited Holmes with the idea.
Blood testing
Also in “A Study in Scarlet,” Holmes
declares: “I have found a re-agent which is precipitated by hoemoglobin, and by nothing else … it gives us an infallible test for blood stains … The old guaiacum test was very clumsy and uncertain. So is the microscopic examination for blood corpuscles. The latter is valueless if the stains are a few hours old.”
Holmes’s discovery does predate the first reliable blood test in real life by more than a decade, either the
Uhlenhuth Test created in 1900 or the
Kastle Meyer Test created in 1903.
Holmes is right that the
Guaiacum Test — invented in 1864, using tree resin acid to
turn bloodstains blue — is inconclusive, but it is fairly accurate and in fact, still used today.
In truth, the
Teichmann Test had been in use since 1853, a
conclusive test based on microcrystal formation in reaction to hemoglobin. This is presumably the microscopic examination Holmes was referring to. While it does require a microscope and is not conducted on-scene, and bloodstains that are insoluble or diffused can result in a false negative, Holmes was wrong that the test is only effective for fresh blood. It’s been
successfully used to identify stains as old as 20 years.
The reality of fingerprints
American science journals proposed using prints found at crime scenes
to identify suspects as early as 1877, and in 1880, Henry Faulds, a Scottish physician working in Japan,
used fingerprints to identify a burglar, writing about the case later that year
in the British journal “Nature,” which Doyle was a reader of.
Doyle wasn’t even the first to write about it in fiction. Mark Twain beat him to it in
1883’s “Life on the Mississippi,” where a murderer is identified using a bloody thumbprint, and in 1884’s
“The Tragedy of Pudd’nhead Wilson,” in which a lawyer uses methodical fingerprinting to solve a murder and prove it in court.
That said, the
first real-life murder case to be solved using fingerprints wasn’t until 1892 in Necochea, Argentina. Scotland Yard only began employing a rudimentary fingerprint system in 1894, and only as an auxiliary to anthropometrics, which identified criminals by physical characteristics like skull width and foot length. Fingerprinting became
standard practice in England in 1901 and was first presented in court a year later.
The first fingerprinting unit in the US was
established in New York in 1903, spreading to the rest of the country following a
successful demonstration at the 1904 World’s Fair. The
first criminal trial to present fingerprint evidence was in 1910.
Examining documents as evidence
Whether Holmes was the first to identify a culprit through
typewritten document examination is harder to answer.
In 1891’s “A Case of Identity,” he matches the keystrokes on a typed letter sent by his suspect to letters sent by the criminal,
stating that “a typewriter has really quite as much individuality as a man’s handwriting.”
This technically predates the earliest professional text to reference typewriting identification, 1894’s
“Disputed Handwriting,” as well as the
first trial to hear expert testimony on typewriting, provided by a typewriter repairman, in 1893. But typewriting analysis was allowed in US courts even before then, and by the 1890s it was common enough that
several technical manuals were written, even if not by forensic experts.
Still, Holmes was at least an early adopter. He also
muses about writing a monograph “on the typewriter and its relation to crime,” years before the first comprehensive text on the subject, 1910’s
“Forensic Document Examination.” The FBI didn’t establish a
document section until 1932 and
the Scotland Yard until 1935.
Preserving the crime scene
In several stories, he comments on the need to record and conserve anything found at a crime scene, no matter how small or trivial. In 1891’s “The Boscombe Valley Mystery,” he bemoans the contamination of a crime scene by a search party’s footprints,
noting “how simple it would all have been had I been here before they came like a herd of buffalo and wallowed all over it.”
During the Victorian era,
crime scenes were recognized as such, particularly in murders, and they were examined by police inspectors and sometimes a pathologist or local doctor. But there was
no protocol, no awareness of trace or latent evidence and no imperative to protect the scene from tainting.
The
first forensic manual, “The Washing Away of Wrongs,” was published in 1247 China. The first requirement to
present (and so preserve) medical evidence in murder cases was in 1507 Germany. The
first guidelines in England for observing and collecting facts in a crime scene were included, briefly, in an 1844 King’s College manual, “Principles of Forensic Medicine.”
It wasn’t until Hans Gross, an Austrian judge and criminalist, published his influential “Handbook for Criminal Investigators” in 1893, considered the first systematization of crime investigation, that it was
put in official writing: “Never alter the position of, pick up, or even touch any object before it has been minutely described in the report.”
Though Gross’ handbook postdates Holmes,
there’s no evidence to support the popular claim that he was directly inspired by him — or vice versa. What’s more likely is that Gross and Doyle, both medically trained men at the cusp of the age of science, arrived at the approach concurrently.
What’s the verdict?
The claim that Sherlock Holmes invented modern forensics is highly exaggerated, but it’s not completely untrue.
Doyle applied the scientific method to detective work before the police did as a whole, and in several instances pioneered concepts and techniques ahead of their time. But the turn of the last century was an era of rapid advancement in science, technology and medicine, and Holmes embodied its spirit. He had the benefit to practice in fiction what was still theoretical in reality, and his innovations often shortly preceded their real-life equivalents.
What’s fair to say is that Sherlock Holmes was indeed a significant influence on the field of forensic science. He made its ideas accessible to the masses, popularized it as a unified field of knowledge, and inspired generations of criminal justice professionals who went on to solve crimes and save lives. That’s anything but elementary.