Fingerprint identification has a number of advantages which make it a popular method of identification in settings ranging from police stations to secured facilities. This method of identification is accomplished by comparing fingerprints from someone against a database of known fingerprints. If the sample fingerprints match fingerprints in the database, it is considered a positive match. It is important to note that many identification systems which use fingerprints go for a statistically significant match; rather than matching the whole fingerprint, they look for key markers which can be used for comparison.
One big advantage of fingerprint identification is that it is very well accepted in the legal community, among law enforcement, and the general public. It has a long history in forensic science, complete with numerous studies which back up the use of fingerprints for identification. This venerable history gives it weight and credence which are not available to newer identification systems. In addition, fingerprint identification is widely perceived as highly accurate and very reliable, since the statistical chance of two people on Earth having identical fingerprints is very low.
The accuracy factor is important, as mistaken identity is hard to do when fingerprints are collected and studied properly. However, this can also be a pitfall; because people rely so heavily on fingerprint identification, if fingerprint evidence is not collected, stored, or handled properly it may result in a false identification which people will believe is valid because they view fingerprinting as highly reliable.
Fingerprint identification can also be accomplished with an automated system, which reduces the amount of human work required to make a positive match. This can also increase security; if an automated system controls access to a site with fingerprint identification, for example, it's impossible to bribe or trick the system to get in, as might be a problem with a human.
Fingerprints also tend to remain consistent throughout life, unless someone experiences an accident or works in an industry with caustic or hot materials which damage fingerprints. This can be extremely useful in some settings. For example, parents who fingerprint their children and put the fingerprints on file can be assured that if their children are kidnapped and later identified, the childhood fingerprints can be used to make a positive match even if the children have matured. This consistency, however, can be another problem; if people do experience changes to their fingerprints, they may find it difficult to verify their identity.