He’s crazier than a shit-house rat. But... crazy AND guilty.
If my dog got rabies I would feel bad for it. It's not the dog's fault.
I would still shoot it, because it is a danger to everyone so long as it lives. But I would feel really bad about it.
I feel bad that this guy is crazier than a shit-house rat. Regardless of how he got that way, he still needs to be shot or locked up for life.