This is a controversial topic; I recognize that. I also will not pretend to be an expert on gun safety or public policy. However, I do know a lot about mental health, and I do consider myself an expert on promoting safety among those with mental health diagnoses.
In mental health fields, when someone is at risk of hurting themselves or another, we assess for three primary things: Plan, Intent, and Means. Often, people have a plan for how they might commit a violent act, but they do not intend to do it. Other times, people have a plan and intent but lack the means. It is only when people have a plan, the intent to execute the plan, and the means to execute the plan that we are truly concerned about safety. Any missing ingredient of the Plan + Intent + Means equation is a barrier to harm. This is why it drives me insane when mental health gets blamed for mass shootings (or even violent crime) in this country.
Yes, mental health concerns are part of the equation in many cases. However, even the most motivated person cannot commit a mass shooting without a gun. To promote public safety, we need to limit the plan, the intent, AND the means. If we are successful in just one of these areas, we could save a lot of lives. It is reckless not to address every component of the equation, and it irks me to no end that our policy makers cannot see this.