Since no two humans share the same patterns, fingerprinting is an incredibly important part of forensic detective work. It’s been used as standard practice by detectives since the 1890s, when Sir Francis Galton published the first book on the subject. 

Essentially, the friction ridges on our fingers which help us grip are all unique. The shapes they form are known to print examiners as arches, whorls, and loops. The latter pattern is the most common – looped prints account for around 60% of the world’s population. Criminalists take impressions of prints left at the scene of the crime and compare them with those of a suspect.

The classification system was developed as early as 1899 and it’s still largely in use today. However, fingerprints are now scanned and digitally recorded on vast computer databases that can be checked for matches in a fraction of the time it once took a small army of investigators.