He ought to be forced to submit to DNA sampling, a few lineups and be investigated for his admissions of rape.
He should be considered a suspect in any unsolved rapes. And submitting a DNA sample is the very least he ought to suffer. He brought it on himself.
He may be a decent person who was having a bad day, especially if he doesn’t have any prior arrests. He strikes me more as Virgil Starkwell nebbish, than Jack the Ripper.