On December 6 , 1989 , Marc Lépine entered Arriving a mechanical engineering class at the École Polytechnique and ordered Arranging the women and men to opposite sides of the classroom .

Lépine then moved Motion through corridors , the cafeteria , and another classroom , targeting Aiming women for just under 20 minutes before turning Becoming the gun on himself .

In a search for a rationale since the attack there have been debates Communication over various interpretations of the events , their significance , and Lépine 's motives .

Other interpretations emphasize the effect Influence of Lépine 's history of abuse as a child , suggest Convincing that the massacre was simply the isolated act of a madman unrelated to larger social issues .