When police retrace the history of a serial predator after he is finally caught, they often find that he never had a prior criminal conviction, but did have a prior arrest. That means the only way they are likely to catch such a perpetrator after his first crime -- rather than his 10th -- is if authorities can maintain a comprehensive database of all those who are arrested, just as we do with fingerprints.  -   Jon Kyl     Quotes
When police retrace the history of a serial predator after he is finally caught, they often find that he never had a prior criminal conviction, but did have a prior arrest. That means the only way they are likely to catch such a perpetrator after his first crime -- rather than his 10th -- is if authorities can maintain a comprehensive database of all those who are arrested, just as we do with fingerprints. Jon Kyl