It's Not a Fair Fight!
In deadly force encounters, we know that action beats reaction, and that police are at a disadvantage when trying to identify and respond to pre-attack cues. This is because it takes time to perceive a suspect’s movement, identify an object, interpret an action, decide on a response, and execute the response. While an officer is going through this “mental chronometry,” the suspect continues to take advantage of the officer’s delayed or defeated response.
We see this in the Force Science Institute's traffic stop study results, where officers were able to identify and react to an armed threat in less than .5 seconds but still took nearly two additional seconds to move, draw, and respond with aimed fire. Compare this to “suspects” from previous research who were able to pull a concealed weapon and fire in an average of .25 seconds—with some firing at .15 seconds.
To put these speeds into perspective, it takes about twice that long (.30 seconds) just for the brain to react to a visual stimulus. With these speed advantages, suspects could conceivably fire before the officer perceives any movement and could continue to fire ten or more rounds before the officer can return fire. Edged-weapon attacks can be even faster, with research showing knife thrusts at speeds of .10 seconds!
See my full article at https://www.forcescience.org/news/