The first thing that a person should do, occurs before an active shooter event actually happens. A person should always be aware of the exits in a room or building. You want to have a plan on how to escape if something does actually happen. You do not want to get stuck trying to find an exit, or worse, get stuck at an exit.
Another thing to consider, is that rules stop applying during an active shooter event. A person does not have to leave a building the same way they entered. If you are in a mall, or an arena when an active shooter event occurs, there are other ways out than the ones you used to get in.
In a mall, it is recommended that you run into the nearest store, and locate the door in the back marked employees only, or something similar. Go through that door. There should be another that will lead you to a concrete hallway or loading dock. Follow the hallway and find a way out. Chances are, the shooter will not go through this hallway, since they are looking to do a lot of damage, and that will be done in the main section of the mall, and at its primary exits.
In a sporting arena, try to find a door that is marked for players or talent only. There is a private exit for talent and staff to use to avoid the crowds of fans. Normally this exit is only for authorized people, but in an active shooter situation, that authorization no longer matters.
During these kinds of situation, the shooter is looking to harm as many people as possible. This is easy to do when everyone rushes for the exits at once. This creates a bottleneck and gives the shooter a lot of targets. It is best to avoid those kinds of situations if possible. Looking for another way out could save a person’s life.