Protocol is to sweep the floor systematically as long as they do not hear active gunshots. This is because in the time that the witness saw the shooter on floor 2, they could have doubled back to the first floor. It does nobody any good for officers to beeline to the 2nd floor, and get ambushed from behind from a shooter lying in wait. There is also the potential for a secondary shooter.

I'm a cop, and when we went through active shooter training, this is how we learned. The scenario I went through involved a simulated shooting in a small office building. Same things were involved. We made a 4-stack and started sweeping. At the end of a long hallway we heard shots get fired so we began to bypass rooms and casualties, to rush to the source.

Nashville responded 100% by the book. Make entry with a team of 4 and sweep systematically each room, bypassing locked doors without keys. Keep pushing in this method until you find the suspect. If you start hearing gunshots, begin to rush past ALL rooms until you engage. Any injured or deceased should be noted on radio but otherwise passed over as your job is to eliminate the threat so EMS can get in to do their job.

These officers were brave and are the example of what our officers should look like every day across the country. Yes, there will always be fear. You don't get to not do your job because you are afraid though.