Trees are the usual way they gain access to a roof. But they can also climb old television antenna poles, damaged siding, or from buildings that are within a few feet of the residence. The down spouts should be too smooth for them to climb, but they are strong animals, so that could be a possibility.
If you do not want to remove the animal yourself, you can call a nuisance wildlife control operator (NWCO) to trap and remove the raccoon for you. NWCOs will charge a fee for this service.
If you want to remove the raccoon yourself, you will need to call your local Illinois Department of Natural Resources District Wildlife Biologist to request an animal removal permit. If the situation warrants the removal of the animal, the biologist will issue you an animal removal permit.
Raccoons should be live-trapped in a commercially available trap such as a Tomahawk trap. Traps should be baited with cat food, sardines, or other similar product. Place the trap near the area where you have seen the raccoon. Set the trap in the early evening and check it early the next morning. All traps should be checked at least once a day. Close the trap during the day to avoid capturing animals other than raccoons.
Once you have captured the raccoon, you have several choices. By law, raccoons in Illinois must either be: 1) released on the same property within 100 yards of where the animal was captured, 2) surrendered to a licensed veterinarian who is a licensed wildlife rehabilitator, or 3) humanely euthanized. The biologist issuing the permit will determine the appropriate outcome for each case.