-
First forensic science manual published by the Chinese. This was the first known record of medical knowledge being used to solve criminal cases.
-
First recorded instance of physical matching of evidence leading to a murder conviction (John Toms, England). Evidence was a torn edge of newspaper in a pistol that matched newspaper in his pocket.
-
German chemist Valentin Ross developed a method of detecting arsenic in a victim's stomach, thus advancing the investigation of poison deaths.
-
Anthropometry, a system using various measurements of physical features and bones, used throughout the US and Europe. Using the system, a criminal's information could be reduced to a set of numbers.
-
Juan Vucetich, an Argentinean police officer, is the first to use fingerprints as evidence in a murder investigation. He created a system of fingerprint identification, which he termed dactyloscopy.
-
Victor Balthazard and Marcelle Lambert publish first study on hair, including microscopic studies from most animals. First legal case ever involving hair also took place following this study.
-
Victor Balthazard realizes that tools used to make gun barrels never leave the same markings, and individual gun barrels leave identifying grooves on each bullet fired through it. He developed several methods of matching bullets to guns via photography.
-
Prototype polygraph, which was invented by John Larson in 1921, developed for use in police stations.
-
A sound spectrograph discovered to be able to record voices. Voiceprints began to be used in investigations and as court evidence from recordings of phones, answering machines, or tape recorders.
-
FBI established the National Crime Information Center, a computerized national filing system on wanted people, stolen vehicles, weapons, etc.
-
Japanese researchers develop a dental x-ray matching system. This system can automatically match dental x-rays in a database, and makes a positive match in less than 4 seconds.