http://www.ojp.usdoj.gov/nij/pubs-sum/145534.htm
It's a good read, but the germane bits to this particular topic are:
"Of all psychoactive substances, alcohol is the only one whose consumption has been shown to commonly increase aggression."
and
"Marijuana and opiates temporarily inhibit violent behavior, but withdrawal from opiate addiction tends to exaggerate both aggressive and defensive responses to provocations."
I'd suggest reading the entire article, but I know some people won't, hence the quoting.
A person using weed would in fact be less aggressive than in a normal, unaltered state.
Edit: Is the question now how many people have died from smoking weed? That answer is exactly zero. Period. In all of recorded history.