Another US school shooting...wonder how the press will cover this?, page-16

the very desire to own a gun "for protection" is a sign of mental illness

a rational person realizes that......
1......a gun is more likely to be used in suicide, accident or domestic violence.......then in "defense"
2......the very presence of a gun increases aggression and escalates conflict to lethal consequences

https://www.psychologytoday.com/intl/blog/get-psyched/201301/the-weapons-effect

https://medium.com/nonviolenceny/how-guns-shift-conflict-towards-violence-9916c5bc5194

you could well argue that the presence of guns trigger mental episodes......rather than mental episodes result in gun violence