Bourque, 24, is accused of killing three RCMP officers and wounding two others in a shooting spree in Moncton, N.B., last week.
The former friend, whom CBC News has chosen not to name, says he lived with Bourque for four months last year in the north-end trailer home police searched in the days following the shootings.
He says Bourque never criticized police and never talked about wanting to hurt them. Bourque did speak about a dislike for the government, but nothing that made him worry.
He describes Bourque as a "good guy," who did not exhibit any violent behaviour.
And while Bourque did love his guns, treating them like his "babies," he handled them safely around other people, the man says.
Bourque did not store them loaded and only took them out for cleaning, the young man said during an exclusive interview with CBC News.
The pair would also sometimes go out with friends to shoot pop cans in a vacant area, he said.
The last time he saw Bourque was about two weeks ago, when they spent some time together in their usual fashion, he says.
The next time he heard about Bourque, he was being hunted down by police, with much of the city on lockdown.
He says he was shocked by Bourque's arrest, as were other mutual friends who got together over the weekend.
They all asked themselves whether they had missed a sign and what might have led Bourque to being accused of three counts of murder and two counts of attempted murder, he said.
Link to police shooting questioned
There has been speculation the shooting spree is somehow linked to the death of Daniel Levesque, 30, last year.
Levesque was shot four times by two Codiac RCMP officers in July 2013. The officers were recently cleared of any wrongdoing, following a review by the Fredericton Police Force.
Bourque's former roommate, however, says he's not aware of any connection. Bourque never talked to him about Levesque, he said.
The young man confirmed Bourque's parents did contact the RCMP about their son prior to his arrest.
He says he's not sure what they told police, but he knows the family was concerned because Bourque had stopped going to church and was drinking alcohol and smoking marijuana.
He describes the family as being generous, welcoming and devout Catholics.
He had slept over at their home before and when he ran into some hard times, he says, Bourque's father, Victor, offered to let him stay there.
Bourque drank alcohol and smoked marijuana, he says, but to his knowledge, did not use hard drugs.
He was in and out of jobs over the years, including stints at Wal-Mart, Kent and most recently, Rolly's Wholesale, working the night shift.
Bourque had also had some recent financial troubles, he says, noting his car was repossessed in the fall.
Bourque remains remanded in custody and is scheduled to return to court on July 3.
Const. Douglas James Larche, 40, Const. Dave Joseph Ross, 32, and Const. Fabrice Georges Gevaudan, 45, were shot and killed in Moncton on June 4.
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