In 2008, Vince Li, a mentally ill man on a bus passing through Manitoba committed an unspeakable crime. He heard voices, thought the man sleeping next to him was an Alien, and so attacked and beheaded Tim McLean who was on his way home to Winnipeg.
Li was an untreated schizophrenic suffering from paranoid delusions. Most schizophrenics with paranoid delusions are not homicidal, but a few are. When those few have access to a weapon, they can pose a risk to themselves and others (and the reason we have involuntary psychiatric holds). When they have a semi-automatic weapon they can kill 8, 10, 12, or 33. Or more.
Schizophrenics can plan these homicides. The decent into madness is a tortuous path and many are lucid enough at intervals or have learned how to conceal their plans (remember, they are often paranoid). Sometimes there are signs, but many with this kind of mental illness are so medically and socially disenfranchised that no one notices the gravity of the problem or no one cares to notice.
The shootings in Virginia Tech (2007, 33 dead), Tucson (2011, 6 dead), Aurora (2012, 12 dead) Sandy Hook (2012, 28 dead) and now Washington Navy Yard (2013, 13 dead) share a commonality with what happened in Winnipeg in 2008: unspeakable crimes committed by inadequately treated mentally ill men. Since they murdered, I think it’s fair to say inadequately treated mental illness.
Treating mental illness adequately, even with universal health care is a challenge. I’ll wager percentage wise there are similar numbers of inadequately treated schizophrenics, people with depression and homicidal ideation, and people with psychotic breaks in Canada as there are in the U.S. However, access to guns is more difficult and also guns are far less a part of the culture of violence.
If Li had a gun on that bus in Winnipeg in 2008 it is likely many more would have died. If those mentally ill shooters in the U.S. had been armed with knives fewer people would have died.
The world will always have people who descend into extreme mental illness, it’s just in countries without ready access to guns the collateral damage from a psychotic break (or whatever voices and thoughts drive a mentally ill man to resort to horrific violence) is so much less.