The house on Mallory Crescent was a gray two-story shotgun with brown trim, its garage just a few steps up from the sidewalk.

In the summer months, vegetation spilled out from the flower beds running along the driveway, but by the time investigators from the Toronto Police Service marched up to the address on Jan. 18, the raw Canadian winter had scraped away the landscaping. Police turned their attention to large flower planters stored at the back of the property.

They had arrived at Mallory Crescent because a self-employed landscaper named Bruce McArthur regularly worked on the lawn and stored equipment there. That same day, he was charged with killing two people. Police had reason to believe there might be additional victims. And they believed they knew where they might find them.

Indeed, inside the planters were hidden the dismembered remains of at least three people.

On Monday, McArthur, a bulky-framed pink-cheeked 66-year-old who regularly donned a Santa Claus costume at a local mall during the holidays, was charged with three additional homicides.

Police believe there are more bodies still. Right now, investigators are undertaking the macabre task of visiting the 30 other properties where McArthur worked, collecting more than a dozen planters that police believe contain additional remains.

“It’s a serial killer — alleged serial killer,” Sgt. Hank Idsinga explained at a news conference in Toronto on Monday. “He’s taken some steps to cover his tracks, and we have to uncover these victims.”

He added: “We do believe there are more. I have no idea how many more there are going to be. . . . The city of Toronto has never seen anything like this, so it’s very tiring and draining for everyone involved.”

The gruesome news in Canada’s largest city is unfolding this week against a backdrop of social outrage. Both McArthur and a number of his alleged victims had ties to Toronto’s Gay Village neighborhood. For years, members of the city’s LGBT community had reported disappearances from the area, sparking whispers about a possible serial killer targeting the community.

“We are validated in our concerns, but there’s no joy to be had in that,” Nicki Ward, a community activist, told the Canadian Broadcasting Corp. this week. “Why weren’t we listened to earlier? Perhaps some lives could have been saved if that was the case.”

According to the timeline provided by Idsinga at the briefing, beginning in November 2012, Toronto police launched “Project Houston,” an investigation into the disappearance of three men from Gay Village, all of Middle Eastern descent: Skandaraj Navaratnam, 40; Abdulbasir Faizi, 42; and Majeed Kayhan, 58.  The investigation continued fruitlessly until April 2014. “At the conclusion of the project, no evidence is found which would classify anyone as a suspect in any criminal offense related to the disappearances,” Idsinga said.

But in August 2017, police started a new investigation — Project Prism — looking for traces of two other missing members of the gay community: Selim Esen, 44, and Andrew Kinsman, 49.

They learned that Kinsman had had a sexual relationship with McArthur, police say. Investigators began following McArthur. Eventually, police tracked down a maroon Dodge Caravan that they say McArthur had sold to an auto-parts store outside of Toronto.

“They said it was a high-profile case, but they didn’t tell us that it was related to these missing gentlemen in particular,” the shop owner told CTV News. Inside the Dodge, he claimed, police discovered a trace amount of blood in the vehicle, an assertion so far unconfirmed by authorities.

On Jan. 18, McArthur was arrested and charged with the murders of Esen and Kinsman.

After further investigation and the discovery of remains in the planters, authorities charged McArthur with three additional murders: Majeed Kayhan, 58; Soroush Mahmudi, 50; and Dean Lisowick, 47. Police have not publicly connected the victims to the planters. They said DNA testing was ongoing.

“Majeed Kayhan was one of the males whose disappearance was investigated by Project Houston,” Idsinga told reporters. “Soroush Mahmudi was . . .  reported missing in Scarborough by his family in 2015. Dean Lisowick was never reported as missing, but we believe he was murdered between May 2016 and July 2017.”

The murder charges are not McArthur’s first experience in a criminal courtroom. In October 2001, he was charged with assault with a weapon after attacking a man with a metal pipe, the Toronto Star reported. Although the details of the arrest have not been reported, the paper noted to avoid jail time the defendant agreed to stay away from Gay Village and keep far from male prostitutes.

Idsinga declined to provide further details of the evidence linking the defendant to the victims. Vice News reported that before McArthur’s Facebook page was deactivated this week, it showed the suspect was friends with Navaratnam, one of the missing men targeted in the Project Houston investigation. But police have yet to say if the victims were targeted for any specific reason.

“It certainly encompasses more than the gay community,” Idsinga told reporters. “It encompasses the city of Toronto.”

McArthur is scheduled to make a plea appearance in court Feb. 14.

Toronto Mayor John Tory told reporters on Monday the arrests will “bring comfort to people who are very worried about this whole series of events, across the city, and in particular in the LGBTQ community,” the Star reported.

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