“If it was someone’s pet they should have kept it inside.”
If I catch the cat next door that keeps going underneath my boat cover and peeing in my boat, it’s going to be it’s last rendezvous in my yard. The smell in the carpet is beyond nasty. I’d like to smack it’s owner a good one too!
How about telling the owner where his cat has been going? Assuming you have some evidence that it IS his cat that has made the messes and not some other cat or other animal?