Saving your butt in a gunfight may come down to how quickly to can properly apply a tourniquet to a wounded limb. Yes, shooting the suspect and putting them down is a component of your survival, but if you’ve taken rounds your fight for life may have just started.
The United States military developed a system for trauma care in the field called TCCC: Tactical Combat Casualty Care. The system has a lot going for it, including it is based on what you can to to help yourself in the most common, survivable injuries experienced in combat. While most officers are not encountering IEDs or jumping from helos in a hot LZ, we do experience some of the same injuries that TCCC is designed for.