I hope he is a long way away from any neighbors! That's way worse than the sickos that feed squirrels here in the city.!
I used to have a neighbor with a cat door for his garage. He had nine bowls of cat food out for the local ferals living under another neighbor's shed and woodpile. There was a constant procession of them going across the street in front of my house.Those ferals sometimes used my landscape areas for crapping and my Bichon rolled in it like it was the best perfume ever.
So I bought a Hatsan .22 cal and thinned out the herd every once in awhile. I don't know if it would work on raccoons but it sure does a job on feral felines. I also trapped them. Damned hard to make a quick kill with a .22lr rifle... surprisingly so. Oh they'd die, but not quickly. A 12ga is best. I'd assume that's true for trapped coons too.