Paul Greene, a spokesman with the RCMP, said Justin Bourque was arrested at around 12:30 am. The 24-year-old Bourque had been wanted after the shooting Wednesday evening in the northwest area of the city.
Frightened residents had huddled in their homes for a second night as police scoured the eerily quiet streets in search of Bourque.
A motive for the shootings was not known, and Bourque's neighbors described a withdrawn man who collected guns and was an avid hunter of birds, deer and moose.
Dozens of police officers with their weapons drawn could be seen in a part of the search area, some glancing around buildings. Others, including members of a tactical unit, were patrolling streets within the cordoned off area.
Armored security trucks were also visible. Bourque was wearing military camouflage and carrying two rifles in a picture released by police on Twitter.