MONTREAL/VANCOUVER (Reuters) - The Islamic convert that police say killed a soldier in Ottawa and then rampaged through Canada's parliament before being shot dead was a misfit and perhaps mentally ill, according to friends and family, while his troubled and transient past included robbery and drug offenses.

Mr Michael Zehaf-Bibeau, 32, a Canadian citizen, was identified by police on Thursday as the attacker in the incident that rocked Canada and sent shock waves abroad.

"(He) was lost and did not fit in. I his mother spoke with him last week over lunch, I had not seen him for over five years before that," a woman who identified herself as Zehaf-Bibeau's mother said in a statement provided to the Associated Press.

Police said Mr Zehaf-Bibeau shot and killed a soldier stationed at the National War Memorial in Ottawa on Wednesday before running into the nearby parliament buildings, where he was shot and killed by guards in a flurry of gunfire.

US officials said they had been advised that Mr Zehaf-Bibeau was a convert to Islam.

Several years ago Mr Zehaf-Bibeau was known to have attended the Masjid Al-Salaam mosque in Vancouver, where he met Mr David Bathurst, also a convert to Islam, David's father, Mr John Bathurst, told Reuters.

Mr Bathurst offered Mr Zehaf-Bibeau some work with the family's sprinkler company in 2011, but he only lasted two days on the job.

"We made a mistake in trying to help someone out," Mr Bathurst said, adding that while his son knew Mr Zehaf-Bibeau from the mosque, the two men were not friends.

"We didn't fire him, I don't even remember why he quit. He probably just didn't show up," Mr Bathurst said, adding that the company often employed men from the mosque and from Vancouver's rough downtown eastside neighborhood for odd jobs.

"He was nondescript," Mr Bathurst said of Mr Zehaf-Bibeau, adding that mental illness, not Islam, was behind the attack. "This guy acted alone. He's a nutcase that acted alone."

Wednesday's shooting was the second attack on Canadian soldiers in a week. On Monday, Mr Martin Couture-Rouleau, a 25-year-old who converted to Islam last year, rammed his car into two soldiers in the Quebec town of Saint-Jean-sur-Richelieu and was shot dead by police. One of the soldiers later died.

Mr Zehaf-Bibeau stayed at the Ottawa Mission homeless shelter in a downtrodden part of the city for about 10 days before Wednesday's attack, several people at the shelter told Reuters.

One man, who identified himself only as Randy, said he frequently saw Mr Zehaf-Bibeau praying in the hallways of the mission.

Another man, who identified himself as Jean Claude, said Mr Zehaf-Bibeau did not appear unusual, and mostly kept to himself.

"This whole thing is devastating for people here," he said."We are all wondering, what would make a guy do something like that?"

Court records in Montreal showed Mr Zehaf-Bibeau was born to Susan Bibeau in 1982 after she had a brief relationship with Mr Bulgasem Zehaf.

The two had a rocky relationship but were married in 1989, Mr Zehaf said in an affidavit. "After (his) birth, his mother, Susan Bibeau and I renewed our relationship and I also established links with my son," Mr Zehaf said.

"I was entitled to ... look after his education, his security, and to give him all my love." The parents petitioned in 1995 to change their son's name from Joseph Paul Michael Bibeau to Joseph Paul Michael Abdallah Bulgasem Zehaf Bibeau.

Mr Zehaf was also registered as the child's father at the time.

"We have no explanation to offer. I am mad at our son, I don't understand and part of me wants to hate him at this time,"his mother, a civil servant, said in her statement.

Media reports said his father was a businessman of Libyan descent, and that his son had spent time in Libya before moving to Western Canada to work as a laborer.

The affidavit said his father was a Canadian citizen. A Michael Joseph Paul Zehaf-Bibeau was charged with robbery in Vancouver in December 2011, according to court documents, and was later found guilty of a lesser count of uttering threats.

He also had multiple run-ins with police in the French-speaking province of Quebec. Quebec court records show three 2004 cases involving a Michael Zehaf-Bibeau, born in 1982. That year he pleaded guilty to two drug-related offences and one charge of failing to comply with a judge's order.

At the Ottawa Mission, one resident who identified himself as Mark suggested the man they knew briefly had two sides.

One day, Mr Zehaf-Bibeau "snapped" and acted aggressively with other residents, Mark said. He later apologized.

"It just floors me because he was all right," Mark said."Maybe he was mentally challenged or something. What causes somebody to snap like that?"