The science of DNA testing was developed in 1985 by British person Alec Jeffreys. The genetic proof was initial tested victimization his methodology one year later to unravel a double killing in European nation and to link the suspect to alternative antecedently unresolved rapes and murders within the space. In 1987, an American state assailant became the primary criminal litigant within us to be condemned through DNA. Genetic material collected at crime scenes and preserved conspicuous lockers additionally has become a very important think about exonerating those that were incorrectly condemned of violent crimes. As DNA became the gold customary for distinguishing criminal suspects, the FBI and police departments throughout the U.S. started aggregation databases. in addition, sex offenders altogether state square measure currently needed to submit DNA samples to their native local department. sadly, several crime labs square measure inundated with backlogs of genetic samples and should be unable to method them during a timely fashion. one among the foremost reliable types of proof in several criminal cases is in our genes, encoded in DNA (deoxyribonucleic acid). DNA proof will be collected from blood, hair, skin cells, and alternative bodily substances. It will even be accustomed to solve previous crimes that occurred before the event of DNA-testing technology. just like fingerprints, every individual includes a distinctive DNA profile (except for identical twins, UN agency share identical genetic code). however, in contrast to fingerprints, solely a minuscule quantity of genetic material is required to spot a suspect. This article provides a basic summary of DNA as a supply of proof in criminal cases.