I really think the shooting/hanging stuff is symbolic and wasteful. For the real monsters among us isolate them, get them in the best health as possible then humanely put them down and part them out. We can medically use all manner of parts besides just the most commonly thought of like heart, liver kidneys.
At least this way some tangible good can come from getting rid of these people.
At least this way some tangible good can come from getting rid of these people.