Editor’s note: A previous version of this post listed the “NSA” reference in an email sent from Lawson as the American National Security Agency. It has been corrected to say he was referencing the prime minister’s national security adviser.

OTTAWA – The country’s top military commander already knew Michael Zehaf-Bibeau had mental health problems on the day of the Ottawa shooting, documents reveal.

Gen. Tom Lawson, chief of defence staff, was also aware that Martin Couture-Rouleau, who ran over Warrant Officer Patrice Vincent in Saint-Jean-sur-Richelieu, Quebec two days earlier, was mentally ill.

The debate over whether the suspects, whom Lawson also described as “radicalized,” were driven solely by terrorist ideology is sure to be ramped up as MPs are expected to watch a video on Friday recorded by Zehaf-Bibeau before he shot and killed Cpl. Nathan Cirillo on Oct. 22 last year.

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“Two young radicalized Canadian men with known mental health problems took away the lives of two fine soldiers. It is difficult to fathom,” Lawson wrote in an email to an undisclosed recipient on Oct. 22 at 6:48 p.m.

“But we press on.”

The details are included in almost 500 pages of emails released to Global News under access to information.

The release of the video also comes in the midst of the Conservatives’ anti-terror bill, which the government says will give the intelligence community the tools it needs to make Canadians safer. But critics, including academics and four former prime ministers, have lambasted the bill as lacking enough oversight to protect Canadians’ rights.

READ MORE: RCMP may not release video made by Parliament Hill attacker

On Wednesday, Prime Minister Stephen Harper said he had not seen the Zehaf-Bibeau video, but a spokesman confirmed he has been briefed on its contents.

Harper added that Canadians “are well aware, not just because of the October 22 attacks, but because of what they can see around the world, that unfortunately the threat of terrorism and violent jihadism is very real.”

RCMP Commissioner Bob Paulson has said the video, prepared by Zehaf-Bibeau on his own device, is evidence the attack was driven “by ideological and political motives.”

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Paulson described the video of Zehaf-Bibeau as lucid, deliberate and purposeful, and said a “distorted world view,” not mental illness, drove him to shoot Cirillo and storm the Parliament buildings, before being shot and killed.

He also said Zehaf-Bibeau referenced Canada’s foreign policy as well as his Muslim faith in the video, including a remark about Allah.

But Susan Bibeau has called her son’s actions the “last desperate act” of someone who was trapped in his own mind.

As Global News has reported, Zehaf-Bibeau was also a crack addict who once pleaded in a B.C. court to go to jail to get clean.

READ MORE: Why didn’t Ottawa gunman Zehaf-Bibeau get treatment 3 years ago?

Meanwhile, the public safety committee that is set to see the video will start studying the government’s anti-terrorism legislation, Bill C-51, on Tuesday.

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NDP public safety critic Randall Garrison said he supports the release of the video.

“We’ve said all along that when it was appropriate, the public should see the video, since the government was putting a lot of weight on what it purportedly showed,” he said, en route back to Ottawa from his Vancouver Island riding.

But he said he’s waiting to see a full report from the Sûreté du Québec and RCMP about exactly what happened on Oct. 20 and 22 of last year.

“The video would just be one piece of evidence in regard to what happened in Ottawa. And so, if we’re going to, as the government insists, have to revise our terrorism legislation based on these incidents, then we actually need to know the full story of what happened,” he said.

Liberal MP Wayne Easter said there is no doubt Zehaf-Bibeau committed an act of terrorism on Parliament Hill.

“He’s been called a terrorist by some. We’ll see tomorrow, and get, I think, a better view when we see the video,” he said. Tweet This

Lawson’s emails also reveal that shortly after the shooting, he was concerned with advising the prime minister’s national security adviser that there were no “cross country linkages.”

“I need to be able to report to NSA (National Security Adviser) that we have done a nationwide scan and found ‘picture clean,’ or the alternative,” Lawson wrote at 11 a.m.

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At 11:44 a.m., Lt.-Gen Guy Thibault, the vice-chief of defence staff, informed Lawson there were no reports about incidents from anywhere across Canada, except about gunfire in the Rideau Centre, which was later debunked.

Lawson said this week he will be leaving his post in the fall when his three-year term is up.