While Galton was publishing in England, fingerprinting also took hold across the Atlantic. In 1891, Juan Vucetich, a statistician working for the police in La Plata, Argentina, began experimenting with fingerprinting as a means of identifying criminals. Vucetich devised his own fingerprint classification system (later known as the Vucetich system or “comparative dactyloscopy”), which categorized prints by pattern types and subtypes. He started recording the fingerprints of arrested individuals, initially alongside the Bertillon anthropometric measurements that were then standard.
On June 19, 1892, Vucetich’s fledgling system was put to a dramatic test in the town of Necochea, Argentina – in what became the first fingerprint-based criminal identification in history. Two children had been murdered, and investigators found a bloody thumbprint at the scene on a door. Vucetich was consulted to compare this latent print against suspects. When the print matched one taken from the children’s mother, Francisca Rojas, the truth emerged: she had killed her own children and attempted to blame an innocent man. Confronted with the fingerprint evidence, Rojas confessed, making this the first homicide case solved by fingerprint evidence on record.
After the Rojas case, Argentine authorities were convinced of the technique’s value. Vucetich’s fingerprint system was officially adopted in Argentina in 1903, and it quickly spread to police forces across Latin America. Vucetich continued to refine his method (publishing a book in 1904), and his success provided proof-of-concept globally that fingerprints could reliably identify perpetrators where other evidence failed. Today, Argentina proudly recognizes Vucetich as a founding father of dactyloscopy, and the Rojas case stands as a milestone in forensic science.
Sources:
Visible Proofs: Juan Vucetich and the origins of forensic fingerprinting
