DNA testing is fallible, and therefore should not be used as the basis of convictions  Although DNA detection might have advantages over fingerprint dusting, the test is nevertheless fallible. Environmental factors at the crime scene such as heat, sunlight, or bacteria can corrupt any genetic data. Any DNA evidence must be stored in sterile and temperature controlled conditions. Criminals have been suspected of contaminating samples by swapping saliva. There is room for human error or fraud in comparing samples taken from suspects with those removed from a crime scene. The accuracy of any genetic profile is dependent upon the number of genes examined. Where less than four or five genes can be investigated, the PCR technique serves only to exaggerate any defects or omissions in the sample. In 1995 an 18 month investigation was launched into allegations that the FBI Crime Lab was 'dry-labbing' or faking results of DNA comparisons1. Furthermore, in the United Kingdom, the company used by police to analyse its DNA samples was shown to have secretly kept the genetic samples and personal details of 'hundreds of thousands' of arrested people, stoking fears that, if lost, they could be planted as evidence2. The mere creation of a database cannot be the panacea for crime detection. 1 Johnston, D. (1997, April 16). Report criticizes scientific testing at F.B.I Crime Lab. Retrieved May 19, 2011, from New York Times: 2 Barnett, A. (2006, July 16). Police DNA database 'is spiralling out of control'. Retrieved May 18, 2011, from Guardian: