David Lutz made the comments on Friday after Bourque received five life terms with no chance of parole for 75 years for killing three RCMP officers and wounding two others.
"This tragedy could not have occurred, but for that gun," Lutz said, referring to an M305 .308 rifle, one of the weapons Bourque used in the June 4 shootings. RCMP also recovered a Mossberg 500 12-gauge shotgun.
Lutz told reporters Bourque should not have been able to buy the semi-automatic rifle, which has a range of 250 metres with pinpoint accuracy.
His client — a "young fella who was lost in society," and "got himself immersed in right-wing, gun nut culture" — was the one who pulled the trigger, but part of the blame also rests with Canada's gun laws, he said.
"This gun did not belong in Canada," said Lutz, a longtime member of the Liberal Party. "This is a gun that went to Vietnam. This is a gun that was used by snipers. People in Canada don't need those kind of guns."
"The military needs weapons.… Guns belong in the hands of the police. Guns belong in the hands of farmers, who need them, and hunters during hunting season.
"But in downtown Moncton, downtown Saint John, downtown Toronto, downtown Ottawa — we don't need these kinds of guns."
Lutz contends gun registration is "not enough" and urged citizens to speak out.
"I think that, as a result of this case, Canadians have to start looking at the type of guns that are available in this country and the type of people who are entitled to use these guns," he said.
"Three Mounties are dead, one soldier is dead in Ontario, in Ottawa, because the wrong people had guns."
Canada’s National Firearms Association (NFA) had issued a public statement attacking Canada’s gun control laws following the Mountie shootings.
"It is clear that Canada's excessive firearms control system has failed again," the NFA statement said.
"Incidents like these demonstrate the validity of the mounting evidence that none of Canada's firearms control efforts over the past 50 years have had any effect on preventing violence, or otherwise stopping bad people from carrying out their evil deeds," the statement said.