It’s common when people hear about (police) shootings to wonder why the person kept shooting — because obviously the attacker was no longer a threat (in the eyes of the armchair examiner). This often comes up in the context of “being shot in the back”.
In Force Science Institute #260, there was a presentation titled “Can cops really avoid ‘extra’ shots? A realistic research review.” The premise:
A flashpoint of controversy in some officer-involved shootings is when officers do not immediately cease fire the moment a deadly threat ends and they are no longer in mortal danger.
An officer’s ability to instantly stop pulling the trigger once a “stop shooting” signal becomes evident is not always considered. Instead, the officer behind the gun may face harsh media criticism and daunting legal action alleging deliberate excessive force for firing “unnecessary” extra rounds.
While it may be understandable to cry out in this manner, it tends to ignore the reality of the fact we are human and things take time.
Numerous tests were run to look at things like reaction times. A simple reaction time test? Ranged from 0.17 to 0.5 seconds to react to a stimulus, averaging about 0.25. While that doesn’t seem like much time, it’s still time.
Another test had officers shooting as fast as possible and when given a signal were to stop shooting. How many rounds were fired after the signal? from 0 to 6, with an average of about 2 rounds.
A third test changed the signal from a simple stimulus to one that required perceiving the stimulus, deciphering it, making a decision, then proceeding if the signal was the proper one. This increased complexity caused average reaction time to increase to 0.56 seconds. Remember: that’s average, which means some people were faster and some were slower.
In the end, what is demonstrated by these and other performed tests was that time is involved. A stimulus happens, you must perceive it, process it, decide what to do, then react to it (OODA loop), and that takes time. Think about what we (should have) learned in driving school about maintaining a safe stopping distance. Part of why we maintain a safe driving distance is to account for the time it takes to run through the OODA loop. Something external happens, and what we do in regard to that external thing does not happen immediately: it will take time for us to react, and during that time things continue to happen be it your car continues to hurtle forward or a person continues to shoot.
For further reading on this topic, here’s an article from Greg Ellifritz about how it can happen that someone can be shot in the back.
This is not to say people WANT to shoot more than they need to, that people WANT to shoot someone in the back, that “extra shots” are always excusible under the above logic, or any such thing. It just must be understood that there are legitimate and explainable reasons why things like this CAN happen.