Colorado can add this incident to their "Oooops, we never shoulda legalized POT" file.
There appears to be an uncanny correlation between these white mass murderers and psychiatric drugs. I read an article yesterday, somewhere, that in 31 of the most recent murders (or attempts), as this one is, the shooter was on one of the hard, usually prescription, drugs, it also noted a high percentage of suicides are also related. Interestingly, the mental health community has counseled law enforcement not to inform the public of this fact because others on the drugs may stop using them and become worse. - a very complicated problem. The old damned if you do damned if you don’t dilemma!
Possibly - but most of the nation's millions of pot users are not mass murderers.