Forensic science has changed how crimes are solved, and made it much harder to get away with murder. Scientific analysis of criminals and the scientific identification of culprits functionally began in the late 19th century; this marks the beginning of effective police work. As technology and science has advanced, new fields of forensic science have opened up, including DNA and computer forensic analysis.
In 1892, a woman named Francesca Rojas claimed to have found her two children, a six-year-old boy and four-year-old girl, dead in her home in Necochea, Argentina. Rojas blamed a rejected suitor, Velasquez, claiming that she had seen him fleeing her home.
Velasquez was arrested and tortured, but maintained his innocence throughout the torture, even after being tied to the bodies of the two children overnight. Since he did not confess to the crime, eventually, the police began to look elsewhere to find the killer.
An anthropologist and investigator in the regional Argentinian police office, Juan Vucetich, had an interest in criminal identification, and had heard of the new developments in fingerprinting. He was already using Bertillon’s techniques, a system of eleven measurements used to identify criminals. He sent a man to review the evidence at the crime scene. The investigator found a bloody fingerprint on the door of Rojas’ home.
Police took an ink fingerprint from Rojas and compared her fingerprint to that recorded from the scene of the crime. The two prints were matched, and Rojas confessed to killing her children. She had hoped to eliminate her children to get her boyfriend, who was uninterested in the children, to marry her.
Fingerprinting technology is commonplace today, but was very new technology in 1892. It would be a number of years before fingerprint technology found a home in Britain or the United States. In Argentina, Juan Vucetich went on to begin the first database of fingerprints and introduced the widespread use of fingerprint identification in Argentina.