Although I think that's an absolutely horrific way for a cat to die, and your friend is a complete sicko, I don't know that the police/aspca will be able to do anything. I guess it would depend on the state you live in. I know where I live it is legal for people to shoot their animals, even if they are domesticated, mainly because of the farming in this area. I hope that she can be prosecuted, though, because that is truly sick.
Its not legal in PA to shoot a domestic animal, 18 Pa. CS section 5511(A)
"...Saving just one pet won't change the world...but, surely, the world will change for that one pet..."
Re: F/U on friend killing cat
Its not legal in PA to shoot a domestic animal, 18 Pa. CS section 5511(A)