Monique Lepine woke up in a cold sweat on Sept. 13, 2006.

The radio carried news that a young man had opened fire at Montreal's Dawson College, and she was transported back to the day, 17 years earlier, when her only son went on a vicious shooting spree that left 14 young women dead at Ecole Polytechnique.

Though the news of another vicious, unprompted school shooting sent shockwaves through the city and served as an emotionally devastating reminder to Lepine, she resolved that something good would come of it.

At that moment, she writes in her new memoir "Aftermath" (the French version is called "Vivre") she decided to break her longstanding silence and tell her story after years of avoiding the media.

"Enough. Someone must speak out. By emerging from my self-imposed exile into the public gaze, I have only one goal: Although it may seem impossible, I want to put an end to these killings," she writes.

"One way of attaining that goal is to understand what goes on inside the heads of killers such as my son, Marc Lepine."

"Aftermath" which Lepine co-wrote with Harold Gagne, details Lepine's life -- and her son's -- before and after Dec. 6, 1989. The book covers her divorce from a violent husband when Marc was just five years old, being forced to enter the workforce and the eventual death of her daughter due to an overdose.

The book begins by painstakingly chronicling the hours immediately after the shootings, and it seems clear the period is burned into her memory.

It was a full day and a half before Lepine's son was identified as the shooter.

Lepine describes going to work as a health care consultant on the day of the shooting. Her job was to train nurses and her students were distracted by the horrific event.

She also details how she attended a church prayer meeting that evening, and specifically asked the group to pray for the mother of the shooter.

"While some prayed out loud, I meditated in silence, my spirit far away from that meeting room.

'Poor woman, poor mother,' I murmured to myself. 'How can she possibly go on after such an ordeal.'"

It wasn't until the end of the following workday that she was told by her brother, then her boss, that Marc had committed the worst mass murder in Canadian history before taking his own life -- and her world came crashing down around her.

Survivor's guilt

Another overriding theme is the guilt Lepine, now 70, feels for what happened, and her tendency to blame herself for what he did.

"Over the years I have struggled to understand what could have led Marc to commit such a monstrous act towards those young women. Perhaps he compared them to me because they had chosen to make their way in a decidedly male world just as I had done. Although he never said so, I am certain Marc was angry with me for the way I lived my life."

Lepine writes that she knew her son was having difficulties, that she tried to get him the help she knew he needed, but that he refused to accept it.

She also writes how each year she crosses Dec. 6 off on her calendar like it doesn't exist. But the irony, she admits, is that every detail of that day is imprinted in her mind, never to be forgotten.

Though the book's stated purpose is to provide unique insight in hopes of preventing similar murders, it also seems to represent a form of closure for her.

In the introduction to the intensely personal memoir, Lepine does something she has been preparing and trying to do, for 19 years. She asks for redemption.

"Please, forgive me," she pleads with the parents of her son's victims. "I wanted to say it sooner, but I lacked the courage, I suffered in silence, cursing the injustice done to you. My own pain will never go away. As I pray for you, I still mourn my own son, the killer."