MONCTON, N.B. -- The RCMP took time arming officers with high-powered carbine rifles because it was doing "due diligence" on the deadly weapon, a lawyer told the Labour Code trial stemming from a 2014 shooting rampage in Moncton, N.B.

"Arming general duty members with semi-automatic rifles can have negative repercussions, including increased tensions with the public, which in turn can lead to officer safety concerns," defence lawyer Ian Carter told Moncton provincial court Friday.

"Carbines are designed to kill. Given what is at stake, it was incumbent on the RCMP to analyze the issue thoroughly, not for the sake of appearances, but for the sake of public safety."

Carbine rifles were not available to general duty officers the night of June 4, 2014, and Crown witnesses have testified the weapons could have made a difference in the shootings that killed three Mounties and wounded two others.

The RCMP is accused of allegedly failing to provide members and supervisors with the appropriate information, instruction, equipment and training in an active-shooter event.

The RCMP approved the C8 carbines in September 2011, and Carter said in his opening remarks Friday the force was studying the issue carefully.

He noted Crown witnesses have said carbines "could" have made a difference, not "would" have made a difference.

"The real issue in this case is due diligence," he said.

The force also had to follow a lengthy federal procurement process, he said.

"It didn't matter how quickly the RCMP wanted those carbines, they could not break the law to do it," said Carter.

He said evidence will show the RCMP had high quality training in place at the time of the shooting.

He also noted that the police force is not responsible for the deaths of constables Fabrice Gevaudan, Dave Ross and Doug Larche.

"Justin Bourque caused their deaths," he said, prompting Judge Leslie Jackson to note that the Crown also acknowledged that fact in its opening statement.