Objective
Fingerprint is an important content of crime scene evidence. Criminal technical personnel on-site detection and extraction of fingerprint is an important content of research. Because the scene fingerprints often appear on the complex background, nondestructive extraction need professional technology. Based on the short wave ultraviolet light distribution test technology research on the complex background of various kinds of potential fingerprint extraction method, combined with the self-defined evaluation criteria, the visual analysis is carried out to provide a reference for the extraction and evaluation of latent fingerprints.
Methods
Twelve kinds of common objects at the crime scene were selected as trace carriers, and six types of fingerprints, namely sweat, oil, oil-sweat mixture, occult blood, dust layer reduction, and dust layer addition, were used as the inspection materials. Seventy-two samples were examined by 254 nm shortwave ultraviolet reflectography based on the light distribution test technology. The influencing factors of potential fingerprint enhancement effect were systematically analyzed, and the evaluation criteria were established.
Results
The experimental results show that for different objects, the short-wave ultraviolet special light distribution test has the extraction effect on different trace carriers and different fingerprint, and the fingerprint contrast is different due to the light absorption difference of the objects.
Conclusion
The experimental enrich the method system of fingerprint extraction by light distribution inspection technology and provide a reference for the extraction and evaluation of such fingerprints on site.