Method and device for revealing and extracting scene potential fingerprint

Abstract

The invention discloses a method for revealing and extracting a scene potential fingerprint. The method is characterized by comprising the following steps of: 1, irradiating a short-wave ultraviolet laser light which has a wavelength of 266 nm and is output by a neodymium doped yttrium aluminium garnet (ND-YAG) ultraviolet laser serving as a light source to a detection material on which the potential fingerprint is reserved; 2, filtering environmental parasitic lights by using a band-pass glass filter with the central wavelength of 266 nm, and transmitting a laser image of 266 nm reflected onthe detection material to an ultraviolet camera; and 3, receiving and recording the laser image with the wavelength of 266 nm transmitted by the band-pass glass filter by the ultraviolet camera. The invention also discloses a device for revealing and extracting the scene potential fingerprint. The invention can solve the problems of difficult revealing and extraction of invisible or indistinguishable traces and physical evidences in a criminal case scene, is particularly applicable to the revealing and extraction of the potential fingerprint on a surface of a smooth non-permeable detection material such as glass and smooth paper, and has the advantages of low background interference, high contrast and high revealing rate.

Description

technical field [0001] The invention belongs to the fields of social public safety technology and forensic science, and in particular relates to a method and a device for displaying and extracting latent fingerprints on the spot. Background technique [0002] Since fingerprints were found to have the characteristics of "different people" and "marks left by touch", how to extract the fingerprints left at the scene has always been the focus of forensic science and on-site investigation technology research. With the rapid development of global multi-polarization, economic globalization, and social informatization, the criminal methods of criminals are also rapidly refurbished. Significant changes have taken place in the form, formation mechanism, and technological content of criminal evidence. Therefore, higher requirements are put forward for the ability of law enforcement agencies to discover traces and physical evidence and the level of inspection technology. [0003] The a...

AI Technical Summary

Problems solved by technology

[0008] 1. Since the 254nm ultraviolet reflectance method receives 254nm ultraviolet light on the test material, the background interference is large and there is a disadvantage of low display rate;

[0009] 2. Although the 266nm ultraviolet luminescence method receives 266nm laser light on the test material, the UV camera records a long-wave ultraviolet fluorescence image of about 340nm, so it can only be used to reveal the potential of the surface of the permeable test material such as newspapers and kraft paper. Fingerprints, but the effect of showing potential fingerprints on the surface of smooth non-permeable test materials such as glass and smooth paper is poor, so it cannot be used to show potential fingerprints on the surface of smooth non-permeable test materials

Images