A pretty huge part of the problem is that our police act as vastly inferior substitutes to just proper social services. An incredibly simple and good example of how this could be done better is being demonstrated in Denver, where they have unarmed mental health first responders, because most of the time someone is in crisis they're only a threat to themselves, so being armed only makes the situation worse.
They're also trained to view the public as the enemy (warrior training), making them a walking threat. Our police kill people at a rate many times higher than other comparably developed nations; about 60x the UK, for reference. Yes our gun ownership is higher, but the relatively low rate of police deaths shows that their readiness to resort to violence is unjustified.
If we allocated even half of our police budgets towards social services, we'd live safer lives.