@ Aquila Blanca-
The question for this thread was specifically GUN laws, though, and I had already been wondering the same thing ... which is why I was able to put together my little list. Limiting the discussion strictly to GUN laws, I can't come up with anything I didn't mention in my post above.
Its a felony in NJ (not sure of CT) to be in possession of a firearm for unlawful purpose.
The main point I am trying to make is that this animal broke many laws before he ever took a shot. If there was another law in place would it make sense to think that would be the one to stop him?