I think the point trying to be made is maybe it is not just the weapon gun or otherwise.
You have to lend some credence to the fact that anyone who kills another person whether using a gun / knife / driving drunk / sells drugs cut with poisons / a doctor who does surgery under the influence / a company knowingly selling product that can cause cancer.
The bottom line is a lack of respect for human life. More a moral issue than anything else. Making it illegal doesn't fix that. If you can concentrate on that most everything could change. It is not a new issue it has been around throughout history.
Not that I have a solution - I just think the cause is not being identified.