That article is filled with holes.
Very poorly written piece using anecdotal evidence to try to skew data.
The author writes about a shooting involving a husband high on pot. If the husband was high on alcohol, we would not be debating the legality of alcohol, but rather, talking about the shitty things people do when they are drunk.
Two very different conversations.
I'd guess there is a good chance he was on other drugs at the time of the incident. Whether prescribed or otherwise. Literally every mass shooting incident we've had in the past 20 years or so has involved the shooter being on or coming off prescription psyche meds known to induce such forms of violent psychosis in a small % of patients.