On Tuesday, Toronto police began overseeing the excavation of a drain in front of a house linked to alleged serial killer Bruce McArthur.

The dismembered remains of six people have been found in large planters at the Mallory Crescent home, which 66-year-old McArthur used to store equipment for his landscaping business. For weeks, police have been combing through the property, including thawing and digging through the house’s backyard.

The search through the backyard ended Tuesday without yielding more evidence, though police could be seen removing more planters from the property.

The investigation also shifted to the front of the house Tuesday, with City of Toronto workers chiselling through pavement to access the house’s main drainage system.

“We’re now working with the City of Toronto to access the main drain… just to look for any potential evidence that could help further the investigation,” Toronto Police spokesperson Meaghan Gray said.

Police did not say what led them to search the drain.

McArthur was arrested on Jan. 18 and has since been charged with the deaths of five men, all of whom are believed to have ties to the LGBTQ community. The remains of only one person, however, have been positively identified: 49-year-old Andrew Kinsman, who went missing in June 2017. Police have repeatedly said that they expect more charges to be laid in the case.

None of the allegations have been tested in court.

CP24 crime specialist Steve Ryan says he expects police to return to the house’s backyard once the weather warms.

“They can always come back,” Ryan said. “So any time you do an excavation, particularly when it’s frozen ground, you always have the option of coming back at a later date.”

Police are also searching other properties linked to McArthur.

“We’ve identified over thirty properties that belong to clients of Mr. McArthur’s landscaping business,” Gray of the Toronto police added. “We continue to make our way through searching those properties as well.”

With files from CTV Toronto, CP24 and The Canadian Press