Going back to one of the core issues that
ArmyJerry hit on that I forgot to address is the "scaredy cat" cops. I think any copper in the country can relate to that. There are quite simply officers that have no background or comfort level with violence. I personally blame the modern society and school systems with their zero tolerance on fighting and all that bullshit.
It used to be that by the time you were out of High School a young man had been in enough dust ups to have a reasonable sense of what it is to engage in a sensible level of violence. Nowadays, not so much, and the ones that do would rarely be selected for an academy class.
My street unit tried to select veteran cops from tough beats and young cops that had a reputation for scrapping. We had to use some level of force on basically a nightly basis and at least a few times a month we'd have a "could've shot" or "should've shot them" incident without shooting anyone. Our guys knew the lowest level of force they could effectively use to deal with shit. A 25-30yr old that's never been in a fight panics, freaks the fuck out, and typically overreacts to a threat.
Another dynamic we saw was the reliance on the Taser. It's one helluva tool for what it does, but the Depts started mandating its use in place of hands-on control techniques. That perpetuated a whole breed of officer that had plenty of Tazings but no experience tussling in the gutter. The Dept didn't care because a Taser was easier to deal with than a use of force incident so it became a crutch for way too many guys (and gals) who should've been learning to de-escalate where they could and handle business where necessary.
Good experience teaches good judgement. Unfortunately with the de-policing movement in America young cops aren't learning the streets anymore. It appears that many are shooting someone because they can, rather than they should. Knowing when it's time to actually squeeze a trigger is a factor of experience and the judgment you gain from it. I personally had at least 50 ""could've" incidents, probably 15 "should've" incidents, and only fired my weapon on two occasions, both of which were so insanely justified that I was effectively cleared within hours.
My guidance to young coppers was that if they actually had the time to think about whether they should squeeze a trigger then they probably shouldn't.