Those who make the news are not a random sample, so cannot be validly extrapolated to the whole population.
the preliminary toxicology report from Eugene’s autopsy revealed Eugene, 31, had been smoking marijuana near the time of the incident.
Investigators had hoped the initial tests might lead them to quickly identify other drugs Eugene might have taken which could have caused such psychotic behavior, but the law enforcement official said it will now be at least two months before all the lab work will be completed.
In other words, law enforcement officials know that cannabis alone doesn't cause this sort of behavior. You should learn from them.