Policymakers are increasingly coming to grips with legal issues related to taking DNA samples from people who have not been convicted of crimes. The practice of taking DNA samples from convicted criminals is now largely uncontroversial. The courts have routinely upheld laws that authorise DNA collection from both current and former convicts, and the resulting databases of DNA have become powerful tools to analyse forensic evidence collected from crime scenes. The databases help to clear innocent suspects and redirect law enforcement officials away from unproductive investigations. A trend that is causing significant debate is gathering DNA samples from people who are arrested but not convicted. Some people worry that collecting DNA creates the potential for abuse of genetic information stored in databases. This book explores the background and issues of DNA collection and testing.