Rack em up!
In some cultures, sexual contact with dead prey animals is often a part of the initiation or first-kill rites of young males or serves a ritualistic role in the insuring of a successful season.
As for this guy, I'm sure there are laws against bestiality and necrophilia, but certainly there are none against a combination of the two. I doubt if either the law or psychiatry is really geared up to handle this dude.