"Targeting police in Canada is relatively rare," said Paul McKenna, a political scientist at Dalhousie University in Halifax who studies policing in Canada.
Most police homicides result from domestic disputes, he said, where police are caught in a rapid escalation of tensions and violence.
Statistics Canada data shows that between 1961 and 2012, a total of 136 officers were killed.
The general trend was downward over the decades.
In the 1970s, there were 37 deaths and in the 1980s there were 28. Between 2000 and 2010, 10 officers were killed.
But McKenna said he's concerned so-called active shooter situations common in the United States might come to Canada. He defines the term as one or more people killing multiple victims in a public area .
"We need to be aware this problem could be on the increase," he said.
Pete Blair, a professor in the criminal justice department at Texas State University, has studied 210 incidents involving active shootings in the U.S. between 2000 and 2012.
Between 2000 and 2008, he said there was an average of five attacks annually, but the figure jumped to 15 attacks a year between 2009 and 2012.
By comparison, he said the active shooter incidents in Canada are uncommon.
Blair, who is also the co-author of a recent book on active shooters, said Canada hasn't been immune to active shootings, such as the 1989 Montreal massacre when Marc Lepine killed 14 women at the University of Montreal.
"I said, 'Wow, I hope they don't have a set of these that are starting to go on up there, because you had some bad ones in the past," he said.
His study describes the "avenger personality," where the shooter is targeting anger at one group of society they blame for problems in their life.
"What you typically see is the active shooters come at the end of a downward spiral where they've ... become more and more withdrawn from people, and the shooting part is the last straw of the final event," he said.
McKenna said active shootings are now part of police training, but he has questions about the Moncton case, including how rapidly specialized emergency response teams were called in.
"The gap needs to be closed quickly and ratcheted up to those officers who are the emergency response type of people, and they are mentally and physically ready to deal with these kinds of situations," he said.
Cpl. David Falls, a spokesman for the RCMP in New Brunswick, wouldn't say when emergency response teams became involved because it is part of the police investigation.
The Mounties have training for "immediate action and rapid deployment or the active shooter," he said.Suggest a correction