Actually, imprisonment in general population may be better. When the word gets out he raped and killed a 9 mo. old baby, he will wish he would have been hung.
He will likely, in fact, receive treatment by his fellow prisoners that is very similar to what he did to the child, so maybe this is the best justice.
There are some things worse than death and having him put in general population would be one. I’ll bet there are guys just itching to perform jailhouse justice. But I’ll bet he’ll be kept in the isolation ward in isolation for, you know, his safety.
If he has important connections, the "general population" will be his best friends.