Once pioneers like Galton, Vucetich, and Henry had proven fingerprints’ utility, the method had to gain acceptance in courts and legal systems. The first uses of fingerprints in law occurred in the late 19th and early 20th centuries, as police began presenting fingerprint matches as evidence to identify criminals. One early landmark was in Argentina: the Francisca Rojas case of 1892 was not only the first crime solved by fingerprints, but also one of the first instances of fingerprint evidence used to secure a conviction.
In Britain, fingerprints were adopted by Scotland Yard in 1901, and soon after came the first fingerprint-based conviction. In 1902, a burglary trial in London resulted in the conviction of Harry Jackson solely on fingerprint evidence lifted from a crime scene – reportedly the first such conviction in the UK. A few years later, fingerprints made a high-profile appearance in a murder trial: in 1905, the Deptford Murder Case (the trial of Alfred and Albert Stratton) became the first murder trial in England where fingerprints were used as evidence. A bloody thumbprint on a cash box was matched to one of the defendants, providing crucial evidence that led to their conviction and execution. The successful use of fingerprints in the Stratton trial was widely publicized and demonstrated to the public and legal community the value of fingerprint expertise in serious cases.
Other countries followed suit. In 1906, French police (under Alphonse Bertillon, ironically) solved a murder using fingerprint evidence, and in 1908, fingerprint evidence was used in Canadian courts for the first time. In the United States, law enforcement was initially slower to trust fingerprints, but by 1906–1908 police departments in cities like New York and Chicago were experimenting with them.
A turning point in U.S. legal acceptance came with the case of People v. Jennings (Illinois, 1911). In this case, Thomas Jennings was tried for murder, and four fingerprint experts testified that a print found in wet paint at the crime scene matched Jennings’ finger. The defense challenged the admissibility of this new science. The Illinois appellate court, however, upheld the trial court’s decision to admit the fingerprint evidence, issuing a detailed opinion that fingerprint identification is based on scientific principles and is a valid form of evidence. The appellate ruling in People v. Jennings was the first in the U.S. to affirm that fingerprints are reliable and that an expert may testify to a fingerprint match. The court noted that the fingerprint method was in “common use” by then and that courts are justified in admitting this class of evidence as scientific proof of identity.
After Jennings, fingerprint evidence quickly became legally accepted across the United States. By the 1910s, most Western judicial systems had standardized procedures for collecting fingerprints of arrestees and presenting expert fingerprint testimony in court.
Notably, some early legal challenges did occur – for example, in a 1905 case in India (Emperor v. Abdul Hamid), a court initially ruled that an expert was not even required to testify because jurors could compare prints themselves. Later courts, however, disagreed and emphasized the need for expert interpretation. Such debates were eventually resolved in favor of treating fingerprint identification as a technical field requiring expert analysis.
By the 1920s, fingerprint evidence had attained full legitimacy in courts worldwide. Laws and police regulations were updated to integrate fingerprinting: many countries passed acts that effectively made a rolled fingerprint card part of the record of arrest and allowed fingerprints as proof of prior convictions. In sum, the first decade of the 1900s saw fingerprints evolve from an innovative police technique to a standardized legal tool for criminal identification, supported by a growing body of precedent and the establishment of fingerprint bureaus to provide expert services.
Visible Proofs – Vucetich CaseWikipedia – Harry Jackson (criminal)
The Fingerprint Sourcebook (NIJ)
Gazeta policyjna archiwum
