"I would enjoy shooting this guy"

That worries me, as it seems like a widespread outlook. Makes my blood run cold, actually. I'm not sure I believe you.

Maybe, Tom means that he would be happier, if this guy would never have another opportunity to shoot another women. And if this only, realistically, means that this guy needs to be shot, then shooting him would be acceptable and far better than allowing the possiblity that this guy would be able to continue blowing the brains out of people or similar types of hideous acts.

Is it possible that this guy will become the next Saddam or Hilter? Sure, it's a very small chance, but how about if he remains a common murdering thug for the remainder of his life? Question: would you want your dad to be this type of man? Or do you want to have him as your friend? Or how about, do you want go with guy on a hunting trip? Or do you want him as your real estate salesman?

It's a good possiblity that this guy won't be missed by anyone. And it is also possible that many people might feel quite happy if he is dead.

If the picture of the man publicly shooting the woman, was instead immediately followed by a sniper round going through his skull, that would be an improvement.