I think in a perfect world this would be the case.
How would you justify sending someone like this who gets murdered by the mentally ill?
Your second sentence... I don't know where to start, really. I understand the concern. What is hard for me is seeing the world through the lens that all 911 calls should be treated as potential murder traps.
"Hello, 911, I'm calling because my son has refused to take his medication for the last few days and now he won't leave his room and I'm worried that he might hurt himself. I don't know what else to do"
Mental health experts can respond to this call. If the situation seems too dangerous they back off and ask for armed police. Seems pretty straight forward to me. I don't have to justify them getting murdered. It's a possibility that some random **** happens tomorrow and I get murdered. I don't live my life on edge wanting to be prepared for every possible murder scenario above all common sense.
That's what I mean by our overly heavy handed policing. Where in poor, urban communities they treat almost everyone as if they are most likely trying to kill them, and as a result they kill people far far more often, people who didn't deserve to be killed, than they are killed.
Being a police officer is a bit down the list as the most dangerous job and most deadly job. The highly paid, highly trained, highly regarded pizza delivery drivers have that distinction. They face more danger than police, yet they don't gun you down as you're reaching for your wallet to give them a tip.
I don't want police to be killed. I don't want mental health experts to be killed. I don't want anyone to be killed. But we've skewed this WAY too far in the direction of protecting the shield (police officers) rather than the shield protecting us. Can you imagine body armor that killed the wearer because it had a vague suspicion that the wearer might wander into danger and the body armor kicked into self preservation mode? Police officers sign up to be our shield. They don't get to kill us out of a hyper paranoia about them being hurt. That's not the way this is supposed to work.