The biggest danger American police are traffic accidents. Mostly because they spent a lot of time on the streets and accidents happen. They don't get shot at all that much.

What actually happens is that American police is basically unaccountable. It must be really egregious and on multiple camera for them to face any scrutiny. And even then it is easy for them to engineer situation where it is actually ok for them to kill or be violent. Meanwhile, non-cop is supposed to have perfect self control, perfect awareness of situation and be able to follow mutually exclusive instructions yelled at him from multiple cops simultaneously.

Unaccountable groups of people always end up behaving badly. Be it priests, isolated cults or cops.

this right here, our issue is mostly the accountability. Accountable people are much less likely to apply force when not needed. Trying to remember some citations, but there's really interesting data out there on citizen involved shootings v police ones. and I suspect the accountability is key.