Originally Posted by sefrischling
The Judicial Marshals are on the CSP Trunked System. The Judicial Marshals are as follows
49264 - Statewide Judicial Marshals
49232 - Eastern Judicial Marshals
49200 - Western Judicial Marshals
Those are the talk groups for the prisoner transport vans. The OP is looking for the courthouse security radio frequencies. I believe they use Kenwood TK-380 (UHF) portables. Looking through an old "Official Connecticut Scanner Guide-Seventh Edition by Keith Victor, I found the following UHF frequencies;
I believe these are still in use statewide with a PL of 114.8 according to the book.
Keep in mind that this is information from a book that is quite a few years old. Use these as a starting point and see what you get.