DEA on VHF?

While I continue to receive reports of the DEA transitioning to new P-25 frequencies in various parts of the country, I have seen two reports of what they believe to be new P-25 DEA channels in the VHF hi-band.

Both 173.6000 MHz, N156 and 173.7250 MHz, N156 have been reported with encrypted traffic in the Dallas/Ft. Worth area. The P-25 NAC appears to be what is steering listeners to believe it is the DEA. Although I have seen other federal agencies utilizing the same analog CTCSS tone of 156.7 Hz that the DEA used,  I have not seen other agencies using a P-25 NAC of N156 yet.

There have been subtle indications of a possible move from UHF to VHF by the DEA. I'm also wondering if they have some new multi-band radios and have set up some VHF operations for interoperability with other Justice Department agencies.

The frequencies themselves are previously unassigned or had unknown assignments. 173.6000 MHz, N653 is being used as part of the Federal Interoperability project in Southern California.

UPDATE:
 Add another unknown to this network - 173.8625 MHz, N156 has been heard in use in the same region.