I can't even guess where he's going with this, but to my knowledge, most states allow the killing of attacking predatory animals without a license - the killing of an animal on your own property - without a license - an animal attacking your livestock - without a license - and so forth.
Same reasons more or less for killing a person. If you are defending your life, the lives of your family and neighbors or someone destroying your property - yes you can shoot at them. It's not as though showing a license will change things.
But he at least has a point - shoot a deer without a license, and you'll be fined but almost certainly will not spend a single second in jail. Shoot a PERSON in cold blood and if you have any one of dozens of Democratic attorney generals in your state - you won't either.