Benton IL Federal Building (Franklin Co.)

[W9GC]

Does anyone know any "verified in use" federal frequencies used in Benton? There is a Federal Office building containing a US Marshalls office as well as various other federal agencies, and across the street is the Federal Courthouse.

I've been hunting for any freqs for a while and have found non listed anywhere. I guess my next option move will be to park nearby with a Close Call/Signal Stalker scanner...