Ok, this is a strange one. Actually, as far as I can tell, they are using a Glendale TRS talkgroup (don't have the tgid handy - didn't bring the scanner to work today). It is pretty strange since this is where I hear calls dispatched, and don't hear anything on the MC TRS, or on the old frequencies.
TG 329 Glendale TRS. The calls dispatched on this TG are for the Avondale area. Why on earth this is on this TRS I do not know. They have Maricopa County TRS groups, and they have conventional frequencies, yet it appears they use this TG from another system, strange.