Just call Marcus....
Or have your guy call over to the PD (who I believe is still the lead agency) and have them call Marcus to send over the proper documentation. Worse case is call over to EW EMS and get ahold of Tommy who I think was big into the radio system.
Either way, to cover your ass, make sure your guy has a MOU to be on that system and that his equipment has been approved for use. Some people are sticklers for "approved" equipment and will quickly turn on someone how is using it when the system has "problems"......"your radio crashed everything" acusations wouldn't be the first...