Now would be a good time to find out for certain what services
your local Animal Control provides for trapped raccoons. Perhaps you could have a parent or adult friend make the call, and don't mention the one you just dispatched.
A friend of mine got cited for shooting a raccoon in her yard (cited for discharging a gun in a residential area). She was told by one of the deputies to "call the sheriff's dept the next time she had a raccoon threatening the chickens and they'd send someone out to shoot it for her". She was also told by the attending Animal Control officer that they'd come out to pick it up. Turns out that information was not accurate
Maybe you have more services available in your area, and if so, take advantage of them if ever you trap another raccoon. If not, then you know how to take care of them yourself. Their populations are increasing along with development of their habitat, as well as those of opossums, skunks, and squirrels. Their natural predators are becoming scarce but their available food found in pet food dishes and garbage cans.
It sounds like you tried to be as considerate as possible to this pest, even giving it a tasty last supper. Did you have the can pre-filled with water before putting in the trap? That way the animal isn't waiting in fear as the water rises around it. Folks say it only takes a minute or two of immersion, only 30-50 seconds of struggle, before it goes. If an animal isn't shot in just the right place, it could take at least that long for it to go.
I wish you success with your flock and safety for them!