The radios are from "BearCom" and are marked "BC250D" (No, not Uniden bearcats)
They are 7 channel, and using Spectrum Sweeper they are DMR. I was only able to check the secondary Freq (can't keep it keyed up on main band LOL) and it comes back as 463 Mhz. The only other info is that in order to transmit you have to key up and wait for a "chirp". I always associated that with trunking, but I doubt that could be true since the first two channels hit the repeater, the other 5 are "point to point". Doubtful they could be hitting a trunked system anyplace.
And yes, the building is like a Faraday cage. Partly because it is a super secure facility. Verizon phones can't get service there, and it took a repeater and three different antennas until they could get reception throughout the building.