Upstairs in police station (2 lootable rooms plus jail cell), it's possible to sprint through the wall and be able to move inside the building itself. I've so far managed to find two entry and exit spots. From inside the building you can freely look into every room within the building (except the cell) as well as outside. it's not possible to shoot out of this room

Edit: also works downstairs, second image included with the entry/exit points i've found (green marked entry, red marked exit) {F29315} {F29316}