Forensic DNA analysis was first introduced to the American criminal justice system in the mid-1980s. Since then, DNA testing has become the leading forensic tool both for obtaining sexual assault criminal convictions and for establishing the innocence of criminal suspects and wrongfully convicted defendants. This encyclopedia provides straightforward information on the role of DNA in the American courts. Entries explain the relationship of forensic DNA analysis to microbiology, population genetics, statistics, and the legal rules of the admissibility of scientific evidence. Full texts, preceded by summaries, are presented of all the statutes created by the states and the federal government that address the forensic use of DNA analysis, and the edited text of judicial case opinions that address specific DNA issues. There are many entries on organizations that use DNA testing to free wrongly convicted defendants and on individuals who were released from prison (many from death row) after DNA tests proved their innocence.