DNA is rock solid evidence that convicts the guilty and exonerates the innocent.
How investigators use DNA
Chewing gum, saliva, hair and even cigarette butts left at a crime scene can lead detectives to the right suspect. DNA, or deoxyribonucleic acid, is a unique genetic fingerprint found in every cell of the human body. A trace can yield a DNA profile, which is compared to DNA samples from known criminals or other evidence.
Solving cases without a suspect
Forensic scientists at the State Crime Lab use DNA evidence to help law enforcement solve crimes without an apparent suspect. For example, in a rape case, a victim may be unable to identify the attacker. But a sexual assault kit collected from the victim often yields the attacker’s DNA profile.
This evidence is compared through the state and national DNA database of convicted criminals, the Combined DNA Index System, or CODIS. If the comparison yields a match, the rapist can then be brought to justice.
Confirming suspects and clearing the wrongly accused
experts at the Crime Lab can also help when investigators have identified a potential suspect in a crime. Analysts can compare the suspect's DNA to DNA left behind at the scene of the crime. Results can confirm that a suspect was involved, or can help clear someone wrongly accused.
DNA emphasis solves cases
Expert analysis of DNA evidence has aided more than 2,300 investigations, helping local law enforcement officers solve hundreds of murders, rapes, robberies and other crimes across North Carolina.
Attorney General Roy Cooper and the State Crime Lab have led a dramatic increase in the use of DNA technology by:
1) expanding the DNA database to include all convicted felons, not just violent ones, and certain arrestees;
2) searching no-suspect rape cases against the DNA database to pinpoint suspects;
3) speeding the review, audit, and uploading of convicted offender samples into the DNA database.