At least this site codes them as to type of offense, I have know two people who got put on the registered offenders list over BS.
One was seen peeing on a wall outside and instead of being written up for public urination was busted for indecent exposure, he was rude to the judge so that was what he got convicted of and that put him on the list.
The other was a young man who was 17 and dating a 15 year old girl for almost a year, when he turned 18 her mom called the cops and he was sentenced for statutory rape. When the girl turned 18 they got married but he is still a registered offender.
Don't get me wrong, although I am leery of the hint of vigilanteeism involve sexual predators do not seem to stop and pedaphiles especially just become more dangerous, they need lifelong monitoring.
My personal preference would be that their life would be very short, I believe in the death penalty for violent sexual predators and for pederasts, not for vengeance, but rather because the odds are they will repeat.