Am I a bad person for being so happy about this?
I'd apply a little creativity to the sentence. Tell Johnny Mo that his sentence will be executed at some random time while he's out in the exercise yard with the general population. It might be next week, it might be ten years from now. The sniper would get a phone call, which, upon authentication, will authorize him to kill the prisoner as soon as a clear shot is presented.
I'm a firm believer that killers should be executed in the manner they killed their victims, whenever possible. Let Johnny Mo walk around for a while, knowing there's a bullseye on his forehead, but never knowing the exact time.
No, you are a good dwarf.