According to the database, it's a Moto type 2 system - same type as Baltimore county's.
I don't know if this trick works with a 2096, but it should - if you can hear the CC from Baltimore county's system well, plug that frequency in with the others from Carroll. You should then be able to program it. When you are done, delete the Baltimore county frequency.
This dummy CC trick works well with Uniden scanners, but with GREs??
73 Mike