You must be very specific as to what information you want, and when it occurred. If you want video, you will have to pay for the expense for the tape or any other resources. Most FOIA requests that are paperwork are free unless there's a ton of copies required. I've done a few FOIA requests to the FBI, CIA, NSA, etc and all were free. Here is a sample copy:
Note this looks like a IL form and citations to IL law are irrelevant.