The fingerprint identification method requires that the fingers be cleaned first with benzene or ether, dried, and each finger then be rolled with ink on a glass plate coated with ink. Then carefully press each finger on the card made according to the strict technical requirements, print a light gray fingerprint, clear gaps between lines and lines, so that you can count the number of textures and see the texture Towards. You can also press the fingerprints of all your fingers and thumbs simultaneously.
Fingerprinting includes the identification, preservation, and identification of fingerprints that criminals have left in the process of committing a crime. In the latent fingerprints, the texture structure is not printed on a recording card with ink, but is printed on an object with sweat, oil finger secretions or other substances naturally present on the criminal's fingers. Most latent fingerprints are colorless and must be "developed" or made visible before they can be saved and compared. This is to use a variety of gray or black powder brushes mixed with chalk powder or lampblack fumes and other agents. The submerged fingerprint prints or the printed pattern brushed with powder is attached to the adhesive surface of the tape as evidence.