This can be seen in police shootings vs armed militias at protests.. If police approached every suspect as if the suspect were open carrying a high powered semi auto pistol, they'd be much less likely to approach suspects as they do. They'd be much more respectful, keep a vehicle between them, and focus on de-escalation as opposed to confrontation.

And in a country with 44% of suspects owning a fire arm, to confront someone is the wrong move.

... and the ability (in many/most? places) to retire after 20 years with ~50% pay. SO many of these people give zero fucks about the communities they're policing because they don't actually live in them and, generally, aren't incentivized to do so. They take these jobs because it's the best of a limited number of options. They then adopt a siege/deployment mentality and bulldoze their way through 20 years of service in order to retire early and open a bar, fuck off to Florida, hang out on their boat, etc.