Toronto ? A bagpiper played “Amazing Grace” and flags flew at half-staff Friday as Canadians grappled with the deadliest attack on police officers in 120 years, after four Mounties were slain during a raid on a marijuana farm in a rural western hamlet.

The slayings stunned a nation that prides itself on far fewer acts of gun violence than its neighbor to the south.

“Canadians are shocked by this brutality and join me in condemning the violent acts that brought about these deaths,” Prime Minister Paul Martin said Friday.

The four Royal Canadian Mounted Police officers had been investigating a farm in Mayerthorpe, a small hamlet of some 1,300 people in western Alberta province.

Police identified the four Mounties as Anthony Fitzgerald Orion Gordon, Lionide Nicholas Johnston, Brock Warren Myrol and Peter Christopher Schiemann.

Spokesman Cpl. Wayne Oakes said the four Mounties and the suspected gunman were found late Thursday in a Quonset hut on the farm. A government source told The Canadian Press the suspect killed himself after shooting the officers.

“The loss of four police officers is unprecedented in recent history,” said Bill Sweeney, commanding officer of the Mounties in Alberta. “I’m told you have to go back to about 1885 … during the Northwest Rebellion to have a loss of this magnitude.”

The Northwest Rebellion was an unsuccessful attempt by indigenous rebels to establish an independent nation in the northwestern frontier.

Police identified the suspect as 46-year-old James Roszko. Authorities said he had a long criminal record.

Oakes said the Mounties were investigating reports of stolen property and marijuana on Roszko’s property.

There were 152 homicides by firearms in 2002 in Canada, according to federal statistics, compared with 11,829 homicides by guns in the United States for that same year.

A 1995 law requires every firearm in Canada be registered and each gun owner licensed. But Canada is grappling with an increase in organized crime behind the multibillion-dollar marijuana industry.