I think that we should go back in time to the "island prison" concept on sexual predators. Lets find an island that is way out in the Pacific that has less than 10% escape potential, and put all these animals on the rock. Drop these animals off and let them live the rest of their lives with the same types of animals that they are. They can live in the world that they created and if they survive then ok, if not then OK.
A plane flies over and drops off basic food needs and they survive in "their" world accordingly. Putting these animals on a remote island guarantees that they will never hurt or kill another child again. Write your Rep or Senator and ask them to explore. I seriously think this is the best solution to the life live out of these animals.