Thanks for your replies. I have killed three that I know of with one CB shot in the chest or neck. I use a Streamlight Scorpion in one hand and a laser-equipped Ruger MkII in the other. If the shot isn't right, or there's no appropriate backstop, I don't take it.
I should say that I am acting to protect the fish and plants in my garden pond, which raccoons and possums love to play in and treat as their buffet. My wife hates finding half-eaten fish so much that she bags and disposes of the varmint corpses herself. Only one of the reasons I love her.
Regards to all,