It is my fervent hope that the person that you are describing rots in prison for the maximum sentence allowable.
Having said that, I believe in karma. I believe that the Universe requires a balance, and that this type of heinous creature will reap what they have sown. One way, or another.
I personally don't have much faith in any Legal System. But, that's my own opinion and I hope that the perpetrator will get what he so richly deserves.