Did you get radio IDs to go with the talk group? They would help you identify the user. That said they've long been on my Unknown Wildcard list with multiple hits with both local PDs and USMS. RID of 2908xxx is immigration, 2912xxx is USMS, sometimes with 2024xxx which is state DOC/Probation/Parole fugitive task forceHeard TG 60696 for a few mins on 6/25. It s in the range of Federal TG's, maybe USMS or Immigration, but not listed.
Also heard TG 60695 on 6/17 - sounds like Immigration - no listing either.