Rot in Hell: Ariel Castro

As a Ohio resident and constant taxpayer, I for one am quite glad he hung himself. Wish the state would supply ropes and noose tying class in the penal system.
There are several who need to "check out" before the appeals run out.
But the whole case makes me wonder, how many other "creeps" out there have done or are doing the same thing? Whats more, how many got scared when this news broke and did something worse to their victims?
The world has it's fair share of nut jobs, and they hide in plain sight.