DNA is one of the popular methods used by criminologists today, DNA technique is also known as “genetic fingerprinting.” the name given the procedure by Cellmark Diagnostics, a Maryland company that certified the technique used in Great Britain; Lifecodes, the USA law enforcement agencies do commercial DNA identification used the DNA-Print test technique. DNA or “deoxyribonucleic acid” is a unique genetic code of each individual. DNA represents a double-stranded chain of molecules that winds its system through the center of every nucleated cell in every living creature. From one person to another, the series in which molecules form the DNA chain differs. Within species, the number of similarities is greater than the number of alternations, but because of the uniqueness of DNA, no two intervals are exactly the same, except for identical twins (Bowers, 43). For criminal purposes, DNA is extracted from a sample; it is then mixed with an enzyme that singles out the DNA chain at specific sites. The restriction elements that are created by this process differ in length, and a few of them contain the polymorphic DNA element. Next, the elements are sorted by length, using a method called gel electrophoresis : The elements are put on a gel and an electrical current is applied, causing the elements to move toward the positive electrode. Shorter elements move across the gel more quickly than do longer elements and, after a short time, the elements have lined up on the gel according to size. After the elements have paraded across the gel, the configuration is transferred to a nylon membrane called a blot (Fisher 65). Comparing the elements from different samples to each other, criminologists can tell whether the samples match. In a paternity test, samples of blood are drawn from the individual and compared from the sample found at the crime scene. In a criminal investigation, the samples typically are blood from the victim, blood from the accused individual, and the samples from the crime scene, such as bloodstained parts of clothing the offender was wearing. If the DNA sample matches the sample of the offender’s blood, criminologists are willing to give evidence that the chances of the DNA on the sample coming from the offender are high (Kubic and Petraco 74). These criminologists argue that the probabilities are frequently one in millions or billions that two persons would present an identical DNA code; the odds differ, depending on the people in question because there are racial and gender alternations in polymorphic strands, and a range of features are more common or less so. Therefore, these criminologists believe there is virtual evidence that the accused person commits a crime (Bowers, 76). Another technique used by criminologists to determine DNA strands and similarity was developed by White and by Jeffreys. This technique is known as allele-specific testing. Criminologists use this test developed by the Cetus Corporation, to determine whether certain polymorphic DNA elements, known as alleles, are in a sample. This allows a detailed recognition of the DNA because large numbers of individuals may have any one unique allele present in their DNA. By questioning for a large number of all