In old western movies, people predictably squared up against each other at “high noon” for a “fair gunfight,” and it was always the good guy who was the faster draw. Events like that didn’t happen in real life even in the Old West, and they don’t happen now. Police officers are at a disadvantage in encounters with citizens.
Officers must confront the behavior of aggressors they don’t know, and an aggressor’s intent must be inferred from what he’s already done. The aggressor has the advantage of knowing the outcome he intends and the ability to set the pace at which the encounter unfolds. An officer usually has the advantage of superior training and resources, but other factors in those encounters contribute to a challenging dynamic. Those factors include concern for the protection of innocent people, an inability to control the pace of the encounter, stress associated with balancing potentially lethal choices, and changes in the ability to perceive under stress.
To make the situation more challenging, officers in armed encounters are forced to react to the actions of an aggressor. The aggressor always has a time advantage, since it takes longer for an officer to react than it does for the aggressor to act. Therefore, to protect themselves and the people around them, officers must anticipate potential threats and must be prepared to neutralize those threats before the aggressor acts. A responding officer must continuously assess the threat. If a threat is identified, the officer must decide how to reduce it in a way that doesn’t put others at unnecessary risk. That process takes time, during which the aggressor may be moving toward his objective. Officers may have only fractions of a second to decide how to stop an aggressor.