What defines an active shooter?

An active shooter is defined as an individual actively engaged in killing or attempting to kill people in a populated area. This definition encompasses situations where there is a real and immediate threat to life due to the actions of the suspect. The focus is on the act of causing immediate death and bodily injury, which aligns with the urgency and severity of the situation that term "active shooter" implies. Typically, this involves the use of firearms, though the overarching definition primarily centers on the individual's intent and the resultant harm.

The other options describe scenarios that either do not fit the active shooter criteria or involve different situations entirely. For instance, being confined to one location does not account for the ongoing nature of the threat posed by the shooter. Similarly, an active shooter is not limited to using knives or blunt instruments; the key component is the immediate danger to life, often associated with firearms. Lastly, a barricaded suspect in negotiations represents a different scenario that involves law enforcement tactics distinct from those used in active shooter situations.