There are thousands of families whose loved ones were raped or murdered that are waiting desperately for answers. Many of those have unknown DNA profiles associated with them. The suspects who match that profile have probably been convicted of felonies, but for whatever reason, their DNA has never been collected. This is an issue in Washington State and nationwide.
There was an interesting article in the Cleveland Plain Dealer that shows what can happen if you go back and get those profiles.
That article appears here.