Wow! What a despicable POS that guy was. However, it might actually be better that he’d be spending most of his life in prison. Inmates don’t often take too kindly to child rapists and child killers. Main problem with this of course is that someday the dirt bag may be free again. So, in my best scenario, I’d prefer he spent 20 years in prison before they executed him. And make his life as miserable and frightening as possible until that day.
...then again, as much of a sick lowlife coward that he was, he probably would still have made some friends in prison, enjoyed various privileges, and had a bunch of good days there (without fellow inmates attacking or harassing him). Also, your friend and all of we taxpayers would have to pay the bill for it.