I can certainly agree that "shouty minorities" won't get anything done as exemplified by progress over the past 20 years. The numbers, however are against lax gun laws. Only 35% of households own guns. 65%, a super majority don't. The only thing acting in the favor of the NRA at this time is the super majority, most of them, have favored lax gun laws. If we keep seeing mass shootings at the rate we have lately, the tide will turn against. It may already have. It will no longer be a shouty minority demanding changes to our gun laws. 65% is an overwhelmingly large percentage and will have its way.
Regarding your question about the shooter's mental health. Quite laughable that Trump, the NRA and the reactionary right should bring it up.
I've asked somebody else and they haven't answered. Is the following fake news?
Trump Signs Bill Revoking Obama-Era Gun Checks for People With Mental Illnesses
by ALI VITALI
President Donald Trump quietly signed a bill into law Tuesday rolling back an Obama-era regulation that made it harder for people with mental illnesses to purchase a gun.
The measure sought to block some people with severe mental health problems from buying guns.
Both the House and Senate last week passed the new bill, H.J. Res 40, revoking the Obama-era regulation.
Trump signed the bill into law without a photo op or fanfare.
The National Rifle Association “applauded” Trump’s action. Chris Cox, NRA-ILA executive director, said the move “marks a new era for law-abiding gun owners, as we now have a president who respects and supports our arms.”
https://www.nbcnews.com/news/us-news/trump-signs-bill-revoking-obama-era-gun-checks-people-mental-n727221
So, last year, Trump made it easier for people with reported mental illnesses to obtain guns. After Trump signed that bill into law, even if a person had been treated in a psychiatric hospital, which that kid had not, they can get a gun. Why the sudden change of heart? Has there been a change of heart? I suspect they are playing the old delay and deflect trick, hoping the furor will die down.
In any case --- really? You are claiming that the mental health profession is in charge of deciding who should own a mass murder weapon? The answer is no. But if so, just how will that work? Florida, by the way has a deplorable mental health system. It's not up to the task of screening the population to decide who should own a gun. Not even close. I'm all for making people diagnosed with mental illness that makes them unable to make good decisions unable to own a gun. That's a very poor first line of defense. Do better than that.