Police carried 180 guns and 40 bayonets out of a residence on a quiet tree-lined street after the occupant was brought down by rubber bullets early Wednesday, ending the incident that had gone on almost a full day.
Montreal police have confirmed they consulted the registry during the standoff to learn about their suspect but wouldn't elaborate on whether it played a role in the outcome.
"It's among the procedures that we always do for interventions where firearms could be (present)," said Sgt. Jean Bruno Latour, noting that the suspect had allegedly brandished a gun at workers on his property and that was the initial tipoff.
"Before we do anything else, we must be sure to know who we're dealing with."
The long-gun registry was scrapped in the rest of Canada last year but remains operational in Quebec following a series of legal injunctions safeguarding the Quebec data and ordering it be maintained while a federal-provincial battle plays out in court.
"While the registration of non-restricted firearms from Quebec is being maintained, the Quebec portion of the long-gun registry is available to police," said Jean Paul Duval, a spokesman for Public Safety Canada, in an email.
"Firearms owners are still required to hold a valid firearms licence to purchase and possess firearms and to register restricted and prohibited firearms, such as handguns. The RCMP Canadian Firearms Program keeps records of firearms licences."
In addition to the controversial registry, and the RCMP program, police had another tool at their disposal. Quebec provincial police also provide information through their database on gun licences in the province.
Latour would not comment in-depth on the force's use of the registry.
However, police in Montreal and other parts of Canada have been vocal supporters of it in the past.
When the 20th anniversary of the Ecole polytechnique massacre was marked in 2009, then-Montreal police chief Yvan Delorme called the registry "essential" and said it had helped police seize weapons from a man who made threats in the aftermath of the 2006 shootings at Montreal's Dawson College.
The 72-year-old man arrested in this week's 20-hour standoff could face several firearms-related charges.
Latour said they could include assault with a weapon, uttering threats, possession of a weapon for a dangerous purpose, careless use of a firearm, and using a firearm in the commission of an offence.
The man's arraignment, which was expected to take place Thursday, has been postponed as the investigation continues. He is in hospital following his arrest but his injuries are not considered life-threatening.
The long-gun registry has deep roots in Quebec, where there has traditionally been strong support for gun control.
Calls for the registry emerged in the wake of the Ecole polytechnique massacre in 1989 where 14 women were slain in a rampage by a gunman at the Universite de Montreal's engineering school.
Many of the advocates for the registry were survivors of the mass shooting or relatives of the victims.
The bill to end the federal registry received royal assent in April 2012, fulfilling a longstanding promise by the government of Prime Minister Stephen Harper.
The Quebec government has fought back, launching a court challenge.
Opponents of the registry called it wasteful and irrelevant in stopping crime. Its supporters, however, including some police organizations, described it as a valuable tool in law-enforcement's arsenal.
And Quebec has argued that it needs the data to support its own gun database — making it the only province with plans to create a replacement registry. The province has argued it would cost too much to start the registry anew.
Lawyers for the federal government have argued that if Quebec wants a registry of its own, it should start from scratch.
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