A total of 222 officers from the Royal Canadian Mounted Police (RCMP) and its forerunner force, the North West Mounted Police (NWMP), have died in the line of duty since the 1870s, including the high-profile shootings of four young officers in near the town of Mayerthorpe, Alta., in March 2005, and the deaths of two Mounties shot near Mildred, Sask., in July 2006.

Const. Douglas Scott was shot and killed in the Baffin Island hamlet of Kimmirut on Nov. 5, 2007. The 20-year-old from Brockville, Ont., was responding to a traffic complaint. The shooting came just a month after another RCMP officer was killed in Hay River, N.W.T. Const. Christopher Worden, 32, was shot on Oct. 6, 2007, after responding to a house call for assistance.

In the early years, the causes of police deaths reflected the harsh reality of bringing order to Canada's sparsely populated and geographically challenging West and North. Nine officers were thrown from their horses, drowned in raging spring rivers or froze to death before the dawn of the 20th century.

Many more died in combat with Métis who sought to establish an independent homeland in the Battle of Duck Lake, among other skirmishes of the Northwest Rebellion.

About 80 RCMP officers died in boating accidents, car crashes, as a pedestrian struck by a vehicle, or plane crashes, according to the RCMP's Honour Roll, which lists the names of Mounties who died while performing police duties.

But 75 officers of the RCMP and NWMP have been killed in the line of duty for merely being a police officer. Here are some of the most chilling cases, as detailed in the Canadian Police and Peace Officers Memorial database of Canadian law enforcers who died in the line of duty.

August 1920: Const. Ernest Usher, 26, is shot and killed while trying to arrest train robbers at Bellewae, Alta.

January 1922: Const. William Doak, 39, stationed at Tree River, N.W.T., is shot to death in his sleep by an escaped prisoner.

October 1935: Const. John Shaw, 39, of the RCMP, and Const. William Wainwright, a municipal police officer from Benito, Man., are shot while transporting three young men suspected of armed robbery in Saskatchewan. The murderers — three farmers' sons aged 18 to 21 wearing three-piece suits — dump the officers' bodies in a muddy slough, where a farmer finds them three days later. The men later try to enter Banff National Park in Alberta, but run into an RCMP spot check. They open fire, killing two RCMP officers: Const. George Harrison, 29, and Sgt. Thomas Wallace, 39. The murderers are themselves eventually shot to death.

June 1962: Const. Elwood Keck, 25; Const. Gordon Pedersen, 25; and Const. Donald Weisgerber, 23, are shot to death while attempting to apprehend gunman George Booth, who is firing his army surplus rifle from the Peterson Creek Bridge in Kamloops, B.C.

March 1974: Const. Roger Pierlet, 23, is working alone on an overnight patrol in Cloverdale, B.C., when he stops a car while looking for vandals. It turns out to contain two men, one of them a Langley man whose brother has died in a high-speed police chase just four days before. The man, who had been looking for a police officer in order to exact revenge, shoots Pierlet in the heart.

April 1978: Const. Thomas Brian King, 40, stops a car for a routine check in the north end of Saskatoon. The two men in the car attack him, forcing him into their vehicle, driving to the South Saskatchewan River and shooting him before throwing his body in the water. They allegedly stopped on the way to the river to brag to friends about what they were about to do, the memorial website says.

January 1985: Const. Allen Giesbrecht, 31, is investigating a report that a man in Vegreville, Alta, is brandishing a shotgun. He and four other officers arrive at the house, which is adorned with signs scrawled with anti-RCMP slogans. Giesbrecht dies after being shot in the stomach while searching the house, despite wearing a protective vest.

January 1987: Special Const. Gordon Kowalczyk, 35, answers a call from a gas station near the Calgary Airport, saying a customer had left without paying for gas. He stopped a suspect, who shot him at point-blank range from his truck before stepping out of the vehicle and firing five more shots at the dying policeman.

March 2001: RCMP Const. Jurgen Seewald, 47, was shot and killed while responding to a domestic dispute in Cape Dorset, Nunavut. The 26-year veteran of the force had only moved to the northern community a few months earlier. The man who was convicted of first-degree murder in the case has appealed, with his lawyer arguing he was acting in self-defence after being pepper-sprayed.

December 2001: Const. Dennis Strongquill, 52, and his partner stop a truck near Russell, Man., intending to cite the driver for failing to dim his high beams. A passenger gets out of the truck and starts shooting. The two officers jump back in their RCMP SUV and start driving toward a nearby RCMP detachment. In the parking lot, the pursuing truck smashes the police SUV into a fence, trapping Strongquill inside. Again, a passenger gets out and fires a shotgun at Strongquill, fatally wounding him before fleeing the scene.

Feb. 28, 2004: RCMP Cpl. Jim Galloway, 53, a dog handler based in Edmonton, was shot and killed during a six-hour standoff in Spruce Grove, a bedroom community just outside the Alberta capital. A 31-year veteran of the force, Galloway was shot dead at the scene as a gunman tried to leave a house while exchanging gunfire with police. The 39-year-old suspect was also hit and died later in hospital.

March 2005: Four RCMP officers are ambushed and shot to death on a farm near Mayerthorpe, Alta. They were investigating reports of stolen auto parts as well as a small marijuana grow operation. The gunman is also found dead inside a Quonset hut — a large metal storage shed.

July 2006: Two RCMP officers, Const. Robin Cameron, 29, and Const. Marc Bourdages, 26, are shot July 7 after a car pursuit of a domestic violence suspect ended near Mildred, Sask. The officers would die nine days later. After an extensive hunt for Curtis Dagenais, the prime suspect in the shootings, he turns himself in on July 18.

October 2007: Const. Christopher Worden was shot in Hay River, N.W.T., a small town about 500 kilometres south of Yellowknife. The 30-year-old was responding to a call from a house for assistance at 5 a.m. on Oct. 6 when he lost radio contact with fellow officers. Two backup officers were sent to the scene and found Worden in a wooded area suffering from gunshot wounds. He died in hospital. Police launched a Canada-wide search for Emrah Bulatci, who surrendered following a standoff in Edmonton five days later. He has been charged with first-degree murder.

November 2007: Const. Douglas Scott, 20, was shot and killed on Nov. 5 in the Baffin Island hamlet of Kimmirut, about 120 kilometres south of Iqaluit. Scott, from Brockville, Ont., was responding to a complaint about an impaired driver late in the evening.