I believe the standard set on 4473 is "involuntary commitment" by a lawful authority which I've always thought to be a very fair standard. I wouldn't want to keep people from getting the help they need under threat of losing their rights (which could happen with any mental health history [e.g. PTSD, feeling "depressed" not to be confused with depression]). And if someone is dangerous enough to warrant confinement then they probably aren't safe with guns.
I also like the due process that was given by the lawful authority (court for civilians).
Where I think it's gone off the rails is the closing of state facilities, which are likely too costly in 2018 in their original form. Judges can't really use the tool of commitment when there is no where to send someone. So we get the red flag laws which infringe without qualification/due process while the person deemed dangerous is still out and about (makes zero sense). I think we'll see more of this unfortunately.
The first thing we can do is stop creating gun free zones. We can't control when a crazy person will strike or what weapon(s) they'll use. We can offer an equal/greater amount of violence to stop the threat, if we stop disarming folks!
The second thing is the death penalty and apply it for mass shootings in the hopes of creating an adequate disincentive for those with the reasoning capacity to evaluate consequences.
The third thing is to acknowledge there are legitimately crazy people who need to be warehoused as cheaply as possible as their families/friends can't care for them or keep society safe. I hate this as a Conservative but I don't see other solutions. James Holmes and Adam Lanza are/were great candidates for this treatment. Everyone around them knew they were dangerous!
All of that said, they weren't going to get a confinement in this case as the murderer was highly functioning and (AFAIK) didn't have a record of violent behavior.
A lot of this is also sensationalized/blown out of proportion to implement gun control. Keep in mind there are 325,000,000 people in the US now. 40 mass shooting deaths in 2018 as of June, WP says 7,075 gun deaths YTD...
https://www.washingtonpost.com/graph...=.6d009f54ab72