When Canadian police officers patrol the streets they have one tool on their service belts they hope not to have to use — their guns. But not every police force in the country uses the same brand or style.

After an officer was shot by his own gun in Winnipeg, questions have surfaced about police gun safety.

Police say the officer had his sidearm in his holster on Aug. 7 when he opened the car door with one hand, holding his lunch in the other. As he sat down, the gun somehow went off, a bullet striking him in the lower leg. He suffered three severed arteries and as of late last week remained in hospital.

Police are looking into whether the gun, a Glock 35, was faulty and if there have been similar incidents in other police departments.

In Canada, the most common brand choices for police are Glock and Smith and Wesson. The RCMP uses two models of Smith and Wesson pistols for general duty — models 5946 and 3953.

The country's second largest police agency, Ontario Provincial Police, announced in June it had picked Glock as the future sidearm manufacturer of choice for its force of 6,200 officers.

"Glock's safe and reliable design is the number one choice of Canadian law enforcement," the company wrote in a news release at the time.

But Glocks also have gained a reputation online for what some call "Glock leg," which is when a person shoots themselves when holstering or un-holstering the gun while their finger is still on the trigger.

The gun involved in the recent Winnipeg incident is being examined by members of the police firearms unit, but there has been no mass recall of the weapon within the police force.

Gun enthusiasts and experts say that while both the Glock and the Smith and Wesson have benefits and faults, choosing between them often comes down to safety and price.

Tony Di Salvatore, a British Columbia-based firearms instructor and owner of Canadian Firearms Academy Ltd., said while he couldn't comment on the specific gun used by the Winnipeg police officer, there are some key things to look at when it comes to the brands police forces in Canada are most likely to use.

Choosing a firearm

Di Salvatore said there isn't much difference between the brands and it's more difficult to do a one-to-one comparison on different models.

People will have preferences when it comes to the fit, size and how the gun fires. But when it comes to the world of law enforcement, the most important thing is that the firearm is reliable, he added.

"They cannot have hiccups. They cannot have a lengthy process to get the firearm to the shooting stage," he said.

The trigger

The Glock is a single-action only type of firearm. That means the gun doesn't have an external hammer, which strikes the firing pin and ignites the cartridge. Rather than a hammer, a Glock is cocked when you rack the slide; usually the only way to de-cock is to pull the trigger.

It does have a key safety measure. There is a little bar set into the trigger, almost like a trigger within a trigger.

"When you actually put your finger on the trigger you will feel the little bar squeeze, and then when it squeezes to the edge of the trigger you carry it fires," Di Salvatore said.

Glock's design means there are fewer steps when firing. It also means when there's a round in the chamber, the firearm is set to fire.

In contrast, many Smith and Wessons are double-action, which makes them more likely to have an external hammer. It means there's an option to cock the hammer before firing, or have the trigger cock the hammer.

A model 1911 pistol is held in the hands of an assembler prior to being test-fired at the Smith & Wesson factory. Note the hammer at the back of the pistol, on top of the slide. (Charles Krupa/The Associated Press)

The safety

The location of the safety on a gun and how it works depends on the make and model of the firearm, Di Salvatore said.

"Sometimes you will get firearms that are made for the policing world and there is something about it that has been customized," he said.

But safety measures on a Glock, generally, are slightly different than most safety features on other guns, he added.

"It doesn't have what we call a safety switch per say as a separate button, a separate lever. It has a safety system built in," Di Salvatore said.

"So if you go to pull the trigger it actually activates the safety first as part of it (the trigger within the trigger), and then as you continue it releases it. It's all in one kind of motion."

Glocks are usually designed with three safety mechanisms: the bar near the trigger (integrated trigger safeties) and an internal firing pin safety and a drop safety. They are all disengaged when the trigger is pulled and reengaged after it's fired.

Many other firearms have on-off levers, hammers or other external safeties.

Keep your finger off the trigger

Di Salvatore couldn't speak to the incident with Winnipeg police, but he said it's very rare that either brand of gun would fire without a trigger being pulled.

In general, to avoid accidental shootings, fingers should be kept away from triggers, he said.

"Don't put your finger on the trigger unless you intend to shoot the firearm. If you can get yourself into that habit, more than likely, you will be fine," he said. "Use the safety of your firearm but don't rely on it."