The roots of fingerprinting trace back to a case in Kansas in 1903, when Clerk M.W. McClaughtry of a local penitentiary was puzzled upon processing an inmate that he had seemingly already admitted years before. The new inmate, Will West, looked just like an inmate convicted of murder in 1901, named William West, and both men looked like identical twins. Upon taking their physical measurements, police found that both men were physically the same, but were still confused by Will West’s claim that he had never been to the prison before.
Enter a sergeant of Scotland Yard who met McClaughtry at the World Fair a year later. Sgt. Ferrier described how fingerprinting was a method being used overseas for a few years. Inspired to differentiate the two inmates, McClaughtry went back to Kansas to fingerprint both William and Will. The story of the prison doppelgangers still goes down as the case that sparked the adoption of fingerprinting by US law enforcement.