The increased demand for DNA testing comes from two primary sources: (1) the increased amount of DNA evidence that is collected in criminal cases and (2) the expanded effort to collect DNA samples from convicted felons and arrested persons.
All states and the federal government have laws about collecting DNA from convicted persons or arrestees or both: 47 states collect DNA samples from convicted felons, and an additional 21 states collect DNA samples from arrestees.
Read more about the backlog of convicted offender and arrestee samples.
At the end of 2004, the FBI’s Combined DNA Index System (CODIS) contained just over 2 million profiles.
At the end of June 2009, CODIS contained more than 7 million profiles.
The FBI estimates that at the end of 2004, there were 19,000 CODIS “hits” that aided investigations. A CODIS hit can be a match between the profile of a convicted person or arrestee and the profile derived from a forensic case or between two cases. As of June 2009, there were more than 93,000 CODIS hits or investigations aided.