Influence of Sherlock Holmes

Microscope by Seibert from the 19th century

Sherlock Holmes remains a great inspiration for forensic science in literature, especially for the way his acute study of a crime scene yields small clues as to the precise sequence of events. He makes great use of trace evidence such as shoe and tire impressions, as well as fingerprints, ballistics and handwriting analysis, now known as questioned document examination. Such evidence is used to test theories conceived by the police, for example, or by the investigator himself. All of the techniques advocated by Holmes later became reality, but were generally in their infancy at the time Conan Doyle was writing. In many of his reported cases, Holmes frequently complains of the way the crime scene has been contaminated by others, especially by the police, emphasising the critical importance of maintaining its integrity, a now well-known feature of crime scene examination.


Owing to the small scale of the trace evidence (such as tobacco ash, hair or fingerprints), he often uses a magnifying glass at the scene, and an optical microscope back at his lodgings in Baker Street. He uses analytical chemistry for blood residue analysis as well as toxicology examination and determination for poisons. Holmes seems to have maintained a small chemistry laboratory in his lodgings, presumably using simple wet chemical methods for detection of specific toxins, for example "The Adventure of the Naval Treaty". Ballistics is used when spent bullets can be recovered, and their calibre measured and matched with a suspected murder weapon, as in "The Adventure of the Empty House".
Holmes was also very perceptive of the dress and attitude of his clients and suspects, noting style and state of wear of their clothes, any contamination (such as clay on boots), their state of mind and physical condition in order to infer their origin and recent history. Skin marks such as tattoos could reveal much about their history. He applied the same method to personal items such as walking sticks (famously in "The Hound of the Baskervilles") or hats (in the case of "The Blue Carbuncle"), with small details such as medallions, wear and contamination yielding vital indicators of their absent owners.
In 2002, the Royal Society of Chemistry bestowed an honorary fellowship of their organisation upon Sherlock Holmes, for his use of forensic science and analytical chemistry in popular literature, making him the only (as of 2010) fictional character to be thus honoured.