And you know good and darned well that this murderer will be separated from the general population for his own security. Heck, even hardened convicts hate terrorists who want to kill them and their families.
Twenty years is a long time. You never know when some guard just might forget to lock the door between this terrorist and the other prisoners. Accidents happen.
I have heard rumors that some of those douchbags have succeeded in promoting Islam to common criminals they’ve met in prison...which is why terrorists need to be separated from the rest of the jailbirds. Terrorists can “infect” them with Islam, just as terrorists might be at risk of attack themselves.
It is common practice for outgoing Presidents to pardon some federal criminals.
Obama's pardons are going to shock even the most jaded observers.