* Change rules of engagement for police to emphasise de-escalation when possible and gradual escalation when absolutely necessary. E.g. in the UK police won't even have firearms on them most of the time unless specifically called to deal with a suspected incident involving weapons, but even if they do, the focus tends to be on de-escalation and waiting the situation out if possible (e.g. someone sat in a car with a gun for about 12 hours a couple of miles from me some months ago; police just got people out of the way and waited until he calmed down, while neighbours talked to the press and whined about why they didn't just shoot him - he had mental issue and a young daughter that presumably was very happy police were calm and collected).
One of my pet examples here was a case in the US were a guy with an axe was shot after charging a police officer. This was a justified killing in that the police officer was under real threat. But she shouldn't have been in danger in the first place - two of them charged in and confronted the man, instead of clearing a perimeter and waiting for backing. In contrast when I called police (UK) over a possible assault near my house a couple of years ago, they sent 8 officers for an incident with no suspected weapons involved.
Bonus points for:
* Reducing sentences for crimes carried out without weapons significantly. E.g. in Norway, using firearms can easily add 10 years to a sentence that might be 5 or less without weapons.
* Treat any use of weapons to stop e.g. a robber as murder if it's not clearly done in self defense.
Point being that criminals needs to see it as worthwhile to not bring a gun. If it is more dangerous for them to do something unarmed than it is to do it armed, and there's little meaningful difference in sentencing, then why wouldn't they go in armed?
The US has created a perverse incentive for criminals to arm themselves to the teeth.
Part of the reason for the quick escalation is that (American) cops are taught things like the Tueller Drill https://www.youtube.com/watch?v=jwHYRBNc9r8 that claims that an attacker can close 21 feet in 1500 milliseconds and stab a victim so many times that even a fast ambulance response won't save him from bleeding out.
This idea means the cop has to unholster a pistol as soon as any sign of noncompliance is showm, start firing if a person "reaches for their waist", and empty the magazine because this Olympian attacker won't be stopped by a few bullets.
They just "want to get home to their families" despite the fact that car accidents are deadlier to cops and garbage men have more dangerous jobs.
Since UK police only exceptionally carry firearms, they have to play things safer. E.g. respond with more people. Keeping greater distance.
But lots of other police forces have - sometimes heavily - armed police with better results because they effectively act on the basis that using their weapon is an absolute last resort, and so you keep your distance if there's a risk they're armed, and call for backup rather than approach etc.