According to the science, it generally is true that women who commit suicide by gun would commit suicide by another means if they did not have a gun. That’s born out in the analysis I review in the article. It is only somewhat true for men. There does appear to be an impulsiveness among male suicides, where access to a gun increases the likelihood of men committing suicide. It’s not an extreme relationship, but it is a relationship.
Honestly, if we’re going to use statistics, mathematics, and data to formulate our approach to “gun deaths,” mass shootings do not deserve a single sentence worth of consideration. They are a statistical blip, not worth even discussing. I know that sounds cold, and terrible, but math is math. That said, school shooters are almost never suicidal. Go back and check the news stories of all the “true” indiscriminate school mass shooters from Sandy Hook on, and you’ll see they all essentially gave up when confronted by an armed authority figure. General mass shooters I think are a little different, and the reasons why are probably psychological in nature, and related to the differing flavors of ‘crazy’ that each exhibit.