What if it was accident? You never know.
I hit a rabbit once on the trail. I didn't stop, but I did look back, it was dead.
I hit a cat once on an atv. I didn't stop then either. Figured it was dead. Drove by the next day and the thing was still alive, but broken back. I actually felt bad. It was by a house, so I went up to the house and got a hammer from the home owner. It wasn't the homeowners cat luckily, he said it was a wild cat.
BTW, neither of these were intentional.