Juan Vucetich and the origins of forensic fingerprinting
In 1892, two boys were brutally murdered in the village of Necochea, near Buenos Aires, Argentina. Initially, suspicion fell on a man named Velasquez, a suitor of the children's mother, Francisca Rojas. But even after torture, the police could not get him to confess.
Investigators found a bloody fingerprint at the crime scene and contacted Juan Vucetich, who was developing a system of fingerprint identification for police use. Vucetich compared the fingerprints of Rojas and Velasquez with the bloody fingerprint. Francisca Rojas had denied touching the bloody bodies, but the fingerprint matched one of hers.
Confronted with the evidence, she confessed—the first successful use of fingerprint identification in a murder investigation. After the Rojas case, Vucetich improved his fingerprint system, which he called "comparative dactyloscopy." Adopted by the province of Buenos Aires in 1903, it spread rapidly throughout the Spanish-speaking world.