MONTREAL (AFP) - Shocked to learn that two of their own attacked a desert gas plant in Algeria, Canadians are struggling to understand how young men from a quiet, middle-class neighborhood ended up as jihadists.
It was announced by Algerian officials almost immediately after the days-long siege of the In Amenas plant by the Algerian army in January that the pair were among the dead.
One intelligence source said they were Arabs with dual citizenship and were among the 29 Islamists killed in the bloodbath, alongside 38 hostages.
But it was only this week when Canadian media revealed that they were actually former schoolmates who grew up in sleepy London, Ontario that the public's interest was piqued.
The Canadian Broadcasting Corporation named the men as Xristos Katsiroubas, 22, from a Greek Orthodox family, and Ali Medlej, 24. They died during the siege, possibly by blowing themselves up.
The public broadcaster also said two of their friends had traveled with them to Algeria and might be accomplices.
One of them, Aaron Yoon, 24, was arrested in Mauritania prior to the attack and sentenced in mid-2012 to two years in prison for "terrorism," while the other, who was not named, is missing, according to the CBC.
Federal police on Thursday officially identified Katsiroubas and Medlej among the Al-Qaeda-linked fighters, and asked the public's help to fill in gaps about how and why this group had become involved in a deadly plot.
"The RCMP is interested as part of the investigation in determining the circumstances that led to Ali Medlej and Xristos Katsiroubas departing Canada," Royal Canadian Mounted Police Superintendent Marc Richer said.
Both apparently had become angry and alienated at home, and eventually ruptured ties with their families, reports said.
After high school, they also reportedly struggled to keep menial jobs as employers refused to allow them time to pray.
An unclassified RCMP handbook on so-called homegrown terrorist threats says conversions to Islam are often portrayed in the media as a sort of "fast track to terrorist action."
The document notes that Islam is one of the world's fastest growing religions and that most converts are simply that - average people who found that Islam rouses their faith.
But it also states that "converts are a constant in Islamist terrorist plots," and "about half of the subjects involved in disrupted plots in the United States are converts."
The RCMP cites Islamic leaders who fear "the experience of conversion can create an emotional state that is easy for radicalization agents to manipulate."
A former friend told the CBC that Medlej had once told him he did not want to give up women and drinking.
"There're things that I just can't give up in my lifestyle, and it's hard for me to be a practicing Muslim, so why don't I just be a shaheed (martyr) and go straight to heaven instead of all the effort that I can't seem to do," Medlej was quoted as saying by his former friend.
Yoon, of Korean descent, was raised Catholic but like Katsiroubas also converted to Islam. His brother claimed: "It was a positive thing. I obviously had questions, a few conversations about it... He was just a better person, much more respectful."
The brother, who would not give his name, insisted that Yoon traveled to North Africa to learn Arabic and study the Koran, not engage in terrorist attacks.
But Canada's foreign ministry has confirmed Yoon is in a North African jail.
A former co-worker meanwhile said of Yoon's conversion: "He just didn't have that spark. He wasn't that friendly, outgoing guy anymore. He just seemed lost and kind of dead inside," she told CBC.
"He had a lot of friends, He was very sociable. But then he just didn't want to talk to anyone. He didn't open up to anyone. It was just him and his religion and his job. That's it."