Couple of points: deinstitutionalization was largely driven by multiple ACLU suits, raising thresholds for being detained or held for evaluation and changes in effective thresholds for committal. There was a public outcry too: Geraldo Rivera cut his TV journalism teeth with series of exposees on wilobrook in NY, which was medieval in its conditions.
It is also relevant because most other western democracies to which we are compared have lower thresholds, the decision being able to be made at lower levels of authority and expertise, slightly or substantially longer initial hold times, to outright wider definitions of who can be committed. In fact most other developed democracies have subtle but often important differences in (read less) equivalent first, forth and fifth amendment rights compared to the US. I was a manager of an international news organization and we saw quite a few cases of news organizaions with an international footprint where venues "shopped" or chosen by plaintiffs outside of the Us whenever possible. If you could get it in the UK, you did, and anywhere was better than the US because of stronger US first amendment protections. There are also often broader types of evidence from items found with or without warrant. Even double jeopardy protection is not the same in many other countries.
There is something else complex with mental health and guns that is not brought up, but similar to the restraining order conundrum I note below: will "good intention" law, regulations or practices bring unintended consequences that make it worse?
For example anything lower than adjudicated mentally ill presents a problem. it seems logical to limit access to guns for someone undergoing depression, anxiety, anger or impose control. But the thing is, what if somehow recording that, and using that to limit rights, then deters some people from pursuing mental health care or counseling?
Are we going to end up with people who have chronic depression, or temporary severe depression avoiding seeking care or counseling because they can be put on a rights denial list?
2) At risk women who are endangered by specific individuals need to be prioritized by police.
This is a tough one also in danger of unintended consequence.
On balance most people know why restraining orders would be awarded at lower probative burdens than criminal cases. Most sensible people want to make it a low financial burden, and low probative burden for an abused or threatened woman to get an order. We may want hearsay to be allowed, other evidence allowed that would not normally be allowed, and preponderance v reasonable doubt, and in fact a hearing before something less than a judge to expedite a protection order.
The problems on the other side of the balance are two I can see, the first somewhat problematic, the second much more so:
a) are we enabling many groundless restraining orders that are tactics in contentious separations/divorces. There are law journals that estimate 80% to 90% of these order are bogus or simply tactics in some other dispute.
b) can the target of the order lose constitutional rights that would otherwise require criminal justice level adjudication to lose? eg second amendment rights. Is the order itself a pejorative in any other way?
It is a really difficult question. Because if jurisdictions have very low thresholds to get restraining orders, but also pass laws allowing for bars on possession of firearms or confiscation on those low thresholds, we could end in spiral of this being used illegitimately, more and more often.