Caution: What I'm going to type now is going to upset a lot of you

Todays societies, and ESPECIALLY Dutch society, force young people and especially girls to become...err, mature early on. This is the MTV generation, kids being stimulated everywhere they look. In the Netherlands C&A is selling string underware for girls as young as 12! I could think of more such examples, but that would be kind of redundant.
When discos fail to keep 13 year old girls out (and I mean come on, bouncers are doing this several evenings per week- how difficult is it to tell if a girl is 13 or 21?)
Older guys visit those discos, guys who also grew up with MTV etc...on top of this, it's not just a case of an older guy wanting a young girl- the young girl wants him too.
Stuff like that happens outside of discos too. Kids have sex younger and younger when the years pass, and don't mind doing it with somebody way older.
So it's easy to put them in jail, and even easier to give them the electric chair. Ignore the root of the problem and just kill the guy, the mob approves anyway.

I know this isn't what you meant in your post Don, but those guys fall under "pedophile" too and I wanted to add some nuance here. As for the kind of guy you're talking about, ie the old pervert who abducts little girls in cars, I can be brief. Unless we can be very, very certain that in a particular case there's practicly no risk of recidivism, life long imprisonment. Otherwise a long sentence and compulsory psychiatric treatment before released in the open (TBS in the Netherlands allows this lifelong, dunno about the rest of the world)
So no public floggings, live executions on TV, etc