Red Flag laws are acceptable because, before someone has their guns taken away, they do get due process in a court of law.
So somebody gets flagged, they go to court, they get to face their accuser, they get to defend themselves, after all that, a neutral 3rd party (the Judge) makes the call.
That court process is the key thing that defines who can buy a gun and what goes into a background check.
So, for example, the Parkland shooter had been reccomended for an involuntary hold but it never went through a court and a judge. Because of that, it was never applied to his background check and he bought his guns free and clear.
You would think, with all of his problems, SOMETHING would have fouled his background check. Nope! I’d suggest we overhaul what does or does not appear in a background check and make sure kids like this can’t get access to guns.