Prison isn't bad enough

I've had this thought running through my head for a week or so. It started a few weeks back when that first girl disappeared from her home in the middle of the night. Then on the heels of that crime, another Florida girl is gone. It seems to snowball, and every other day you are hearing about children missing, and then found. Dead. This morning, I was awaken to the news that an 18 month old girl is missing from my own city. And, here's my thought. Prison just isn't a horrible enough place to outweigh the subhuman urges these men have. It's just, apparently, a risk they are willing to take, to get their rocks off.
So, I'm thinking we need to up the ante. Yes, I'm talking vigilante justice. These people cannot be reformed, and they obviously cannot control their urges. I say, after someone is convicted of kidnapping, sexually abusing, and then killing a child - we just drop them off into the custody of some ""parents." No chance of parole, so to speak.