The man suspected of opening fire at a Quebec mosque was reportedly a "loner" with far-right beliefs.
Alexandre Bissonnette, 27, is the sole suspect in the shooting on Sunday night (28 January) and was charged with six counts of first-degree murder and five counts of attempted murder on 30 January.
He was not previously known to police, but had become a familiar figure to local activists who said he posted extreme material online.
François Deschamps, an employment councillor who runs a refugee support Facebook page, told the Globe and Mail: "He was someone who made frequent extreme comments in social media denigrating refugees and feminism.
"It wasn't outright hate, rather part of this new nationalist conservative identity movement that is more intolerant than hateful."
Vincent Boissoneault, a student in international relations at Laval University, grew up with Bissonnette and was friends with him on Facebook.
He said they frequently clashed on politics when Bissonnette attacked refugees or expressed support for Marine Le Pen or Donald Trump.
"I wrote him off as a xenophobe," Boissoneault said. "I didn't even think of him as totally racist, but he was enthralled by a borderline racist nationalist movement."
Former high school classmate Simon de Billy labelled him a "nerdy outcast".
"He was an avid reader, knew a lot about history and about current issues, current politics, those kinds of topics," de Billy said. "He was just a bit of a loner, always with his twin brother, didn't have any friends.
"He wasn't physically strong or imposing, and probably got a bit of a hard time, was probably not taken seriously ... He would be kind of made fun of, the butt of the jokes."
Bissonnette could appear in court to be indicted as early as 31 January.