I had the dubious honor of talking to Henry Lee Lucas for about 45 minutes before he was arrested (I worked at the motel he was living in) I had no idea what he’d done but something about that guy literally made my skin crawl.
I have thought about it a lot since then. Yes, I would, provided there was no doubt about guilt, be part of a firing squad.
It was probably his eyes. Psychopaths have no soul in their eyes.
A lot of murderers have soulless eyes. Charles Manson is utterly creepy, too, for the same reason.
Not all psychopaths are murderers, or even criminals. But they all seem to have those empty eyes.