A local parent spotted a "slow and lethargic" raccoon near P.S. 24 on Thursday afternoon. She wasn't sure who to call, and the short answer is to call 311 if you see any animal behaving strangely.
A much more comprehensive answer was presented by another local parent who used to work at a wildlife center:
311 (Animal Control) is probably the best resource in the City for issues like this, but they're unlikely to be able to do anything if the raccoon isn't contained (in a box or a cage trap) or injured. Even slow moving raccoons will probably leave the area before they arrive.
Believe it or not, raccoons are actually more populous in cities and suburbs than in the "wilds," because they thrive on our leftovers and trash. The Humane Society of the United States has lots of good information on its website about raccoons: Link. Another good resource is the MSPCA: link.
Your experience is a good reminder that we should all teach our kids to stay away from wildlife and take care to secure our trash. (And maybe rethink leaving cat food outside overnight.)