Without knowing what this fellow's particular crime was, it is rather dificult to say what might be appropriate. There is apparently one woman who feels that whatever it was, it wasn't so bad.
All I know is that whatever he did, he went to jail, did his time, and got out.
If this is a case of some 16-year old dork who got caught diddling his 15-year old sweetie, maybe he doesn't deserve what he got.
If he's some freak who was, i.e., molesting or abusing 3-year olds, then by all means, kill him, and quickly.
The state is not always right, and there's not enough information in this particular news post to make a sound judgement one way or another.