A forensics question-what methods are used to analyse fingerprints on a murder weapon?
There are two aspects to using fingerprints as evidence -- finding and developing the prints, and identifying the characteristics of the print that are unique and can be used as evidence.
The first part of this has traditionally been done by dusting latent fingerprints. Nowadays, though, there are also many techniques that involve using lasers or other light sources to show the print and then photographing the print.
Once the police have an image of the print, they must look for identifying characteristics in the "friction ridges" that make up the prints. These characteristics are what make our prints unique. Please follow the link to look at basic types of identifying characteristics, with an illustration.
The technique of DNA fingerprinting developed by Alec Jeffreys and his colleagues at Leicester University. In this technique, DNA will be isolated from blood stains, semen stains or hair roots and will be subjected to Southern blotting and DNA hybridization with the help of specific DNA probes. The probes correspond to hypervariable minisatellites in DNA, each made up of tandem repeats of short sequences.
A large number of these minisatellites are scattered throughout the human genome which were first detected in an intron of human myoglobin gene. This will reveal polymorphism in DNA, which has a very stable inheritance.