Police ought to be part of the community, rather than some external paramilitary force. Their behavior would then be modulated through social mechanisms.
Also an excellent point. The selling of non-lethal weapons has been a several-decades long exercise in manufacturers lying about the safety of those non-lethal weapons. Rubber bullets, tasers, it's all bullshit.
How about using electro-magnetic waves to alter the brain function temporarily and provoke it to lose consciousness? Sounds like a hard technical challenge, but we can already deliver effective tranquilisants remotely and use electrical discharge to disable the central nervous system. Just find a more efficient way of doing that.
Ideally you would want some kind of sci-fi weapon that shoots out some sort of impenetrable web/blanket that wraps around the criminal, holding them until you can safely handle them at a later point.
I like the sticky-slime approach. I first read that in Snow Crash. Targets get glued to themselves and anything they touch. There's an enzyme that quickly degrades the adhesive.
It's mind boggling that a centuries old weapon is a supposition for any problem, let alone such a terribly serious one. It's likely that dog catchers are more advanced in their approach.