Get over yourself Nancy, this type of shit has been happening since the beginning of time. Sounds to me like someone has a hard time dealing with life.
...Didn't you hear how the prisoners wanted to kill him? That's why he's in solitary confinement and on suicide watch. Eventually, he'll either get brutally killed, raped, or die of natural causes.
Either way, killing him now won't change what he did, nor prevent others from doing something similar.