This is part of the (repeatable sidequest) "Kidnapping at County Crossing). The area is filled with raiders.
The main room with a construction light is guarded by a laser auto-turret installed on the ceiling. After destroying it though, you can now access the Novice lock in the jail cell after it. Open the lock and get the good loot inside, including a Fat Man, mini-nuke, some chems, and ammo. There's also an Expert Safe and a duffel bag in the jail cell.
Tip: Take note that aside from the Fat-Man and the mini-nuke, everything in this area gets replenished over time or during your next quest-related visit.
Beside that jail cell is another Novice locked door with an Advanced Safe this time and more materials.
The office area to the west has a Novice door leading to a private office. This can be opened by the Chief's key. (His body is found in the bathroom along the corridor leading to the lower jail cells) Examine the file cabinet to get the Cell Key. That office area also has an armor workstation. There's also a Guns and Bullets magazine on the table.
In the corridor from the office connecting to the lower jail, there's a Novice locked bathroom door. Open it to get the contents of the first-aid kit on the wall and the Chief's Key from the skeleton in the stall. You can use this to open the private office in the office area.
The holding cell in the lower floor is where you'll find kidnapped settlers. You can open the cell door using the Cell Key from the desk in the private office.
Finally, the archive room connected to the holding cell has a Novice terminal you can use to activate the protectron beside it.
What is the cell ID for the BADTFL Regional Office?