Videos and photos circulating online that appear to show a sniper at an unsanctioned St. Patrick’s Day party in Waterloo, Ont., on Saturday is a tactical officer who has been used “regularly,” regional police say.

“This is something that happens regularly at planned or unsanctioned events that we know there’ll be a large presence of public members,” Const. Melissa Quarrie, a spokesperson with the Waterloo Regional Police Service (WRPS), told CBC News.

“It does occur at large-scale events, not only with the regional police service, but our policing partners across the province and across Canada.”

She said having a tactical officer is standard protocol for all major events.

“Unfortunately, with the magnitude of unfortunate mass casualty events that have occurred throughout North America and around the world, that really shapes our emergency response strategies for all types of large gatherings.”

After pictures and video of the tactical officer were shared on social media over the weekend, some people said they felt the measure was “extreme” and others wondered if there were “good reasons” to have this type of officer deployed.

Waterloo mayor wants answers

Waterloo Mayor Dorothy McCabe says she was surprised to learn that a WRPS sniper was deployed as part of law enforcement’s efforts to manage the unsanctioned street party.

McCabe said she asked police Chief Mark Crowell why the service felt deploying such an officer at the street party was necessary.

“I have spoken with Chief Crowell and have a more fulsome understanding of the comprehensive plans they have in place,” she said in a statement to CBC News.

“I am confident that police, bylaw and other emergency service partners continue to take a professional approach to the safety and well-being of our community.”

The mayor said she was not told of any concerns about weapons, extreme violence or any other issues that would require such a deployment at the unsanctioned weekend festivities.

“In our two-tiered municipal system, the chief does not report to me as mayor and I don’t sit on the police board.”

She said she’s still looking for more answers.

“I still have more questions, as I know residents do, and I will schedule time to meet with Chief Crowell once the operational period has ended and we have all the details on this year’s event.”