Prison Building

The Prison building can be found in the fenced off broadcast building at the top of Black Mountain.

Location
The prison building is the closest building to you as you enter the Radio station area at the top of Black Mountain.

Companions
Raul Tejada, one of the Fallout: New Vegas companions, can be found in this building. To get to him, you must hack the terminal next to the door. You can also go to the other terminal to the left on the desk enter it, choose entry 6 with gives you the password. Now the terminal to the right doesn't need to be hacked and you can just disengage the lock.