Alberta RCMP say replica guns are so well made these days that it can be virtually impossible for officers to tell the difference between them and the lethal variety.
Replicas are illegal to buy or bring into Canada, but a lot of them still make it in across the U.S. border.
A 62-year-old man was shot and killed by RCMP officers in Canmore, Alta. on Monday after allegedly pointing a replica at officers.
The imitation firearms have come a long way, said Alberta RCMP spokesman Sgt. Patrick Webb.
"It used to be that replicas were plastic, crude, and maybe easier to discern at a distance," Webb said Wednesday. "It is extremely difficult right now to tell the difference. They are very, very accurate."
The 9-mm Smith and Wesson semi-automatic pistol replica in Monday's shooting was even stamped with the emblem of the company it was designed to imitate.
"There's no company in the world that will say these guns are being made so criminals can fake a real weapon. That is not the purpose. These replicas are made to be entertainment value," said Webb.
"What happens is when those same weapons are used on the street, then the whole question of whether those weapons are real or replica becomes much, much more important."
He said using a replica in a crime is considered the same as using the real thing, when it comes to the law.
One Calgary gun expert said replicas are easy to find.
"We have a big border, and the thing is in the States they are very common, in Europe they are very common, so people will buy them for kids and bring them in," said J.R. Cox, owner of the Shooting Edge, a gun dealer and shooting range in Calgary.
Cox said it's also easy to get replicas online.
"There's only so many police, there's only so many customs people, there's only so many inspectors," said Cox.
"They are looking for drugs, they are looking for real guns, they are looking for explosives, they are looking for things like this which have a little higher priority than going to check out toy stores for replica firearms."