A former Canadian soldier accused of killing an unarmed Taliban insurgent has written a new book about his experience in the military, but he carefully avoids discussing what actually happened in the so-called mercy killing.

Robert Semrau, 36, was demoted and dismissed from the military in a 2010 court martial for second-degree murder and attempted murder in relation to the 2008 shooting. He was acquitted of those charges but found guilty of disgraceful conduct.

According to witness reports, Semrau shot and killed an insurgent who had been mortally wounded in a firefight with Canadian and American troops.

Semrau never testified during his court martial, and told CTV’s Canada AM he decided not to write about the incident in his new book “The Taliban Don’t Wave.”

“I’ve never admitted anything. I’ve never said what I did or didn’t do. I’ve told my wife the truth of that moment,” Semrau said.

“In the book, when we get to that moment, I leave it as a matter of public record. I say what was said at the court martial, that’s basically what I said in the book. I’ve chosen not to get into that moment for personal reasons. “

Instead, Semrau said he wanted his book to be about “the bigger picture, the broader context” of what a soldier experiences in Afghanistan, so that a civilian reader could gain an accurate perspective on what the battlefield is truly like.

“This is what Canadian soldiers go through, this is what they have to deal with, the horror, the travesty, the terrible things soldiers have to deal with but also moments of levity. There were comedic things that happened. I tried to be true to that, when it’s funny, it’s funny, when it’s sad, it’s sad -- but it’s all real.”

In the book, Semrau defends his silence and sheds no light on his motivation for shooting the wounded insurgent.

"As a Canadian citizen, I had the right to remain silent during my trial. I could not be forced to testify," Semrau writes.

"I chose to remain silent during my murder trial, and I never gave testimony on the stand, nor did I make a statement for the police. The truth of that moment will always be between me and the insurgent."

The judge Lt.-Col. Jean-Guy Perron told Semrau at his sentencing that his conduct on the battlefield had been "shockingly unacceptable."

"Your actions might have been motivated by honest belief you were doing the right thing," Perron said. "Nonetheless, you committed a serious breach of discipline."

Perron also told Semrau, a captain at the time, that he had set a poor example for his own troops.

The judge said the shooting was "completely out of character" for Semrau, but was also done without regard for the rules of the military.

Perron dismissed Semrau from the military without disgrace, meaning that he could work for the Crown or the government in future. He did not order Semrau to serve any jail time.

Semrau told Canada AM he still struggles with the memories of his experiences in Afghanistan.

“Yes I’ve had some bad dreams, yes I think about Afghanistan every single day but I don’t think you could find a soldier whose seen those things and has been put in those situations and doesn’t have the odd bad dream,” Semrau said.

With files from The Canadian Press