DNA

Definition from Nolo’s Plain-English Law Dictionary

Deoxyribonucleic acid, a double chain of chromosomes in the nucleus of each living cell, whose combination determines each individual's hereditary characteristics. Because each person's DNA is different and is found in each living cell, testing the DNA of a person and comparing that to the DNA found on a drop of blood, hair, or other body substance, can be used to help identify the perpetrator of a criminal act. DNA tests performed on physical evidence years after a trial have repeatedly proved that convicted people on death row did not commit the crimes for which they were sentenced.

Definition provided by Nolo’s Plain-English Law Dictionary.