Toronto police officers monitoring the movements of accused serial killer Bruce McArthur decided to apprehend the 66-year-old landscaper shortly after they saw a young man enter his Thorncliffe Park apartment on Jan. 18, a source confirmed to CTV News.

The source told CTV that when police officers entered McArthur’s apartment, they found the young man tied to a bed. The man, according to the source, was freed by police and was not injured.

Evidence found shortly after the arrest prompted investigators to lay two first-degree murder charges against McArthur in connection with the deaths of Salim Esen and Andrew Kinsman, two men who were reported missing last year and had ties to the Church-Wellesley Village area.

At the time McArthur was charged, police said no bodies had been recovered. Police would not say what evidence was discovered to indicate that the homicides had occurred but a source confirmed to CP24 that the evidence involved photographs.

On Monday, police announced that McArthur had also been charged in the murders of three more men, identified as Majeed Kayhan, 58, Soroush Mahmudi, 50, and Dean Lisowick, 47.

Kayhan, who was one of the missing men identified in Project Houston, a 2012 police probe into the disappearances of three men from the Church-Wellesley Village area, went missing in October 2012.

Mahmudi disappeared in August 2015 and was reported missing by his family in Scarborough one month later.

Lisowick, an occupant of the city’s shelter system, was not reported missing but police believe he was killed between May 2016 and July 2017.

[A look at Bruce McArthur's alleged victims]

Back in December 2017, Police Chief Mark Saunders said there was no evidence linking Esen and Kinsman’s disappearances.

“As soon as that information was received, as soon as that evidence was received that had the ability to make an arrest we exercised what we had to do,” Saunders said while speaking with CP24 on Tuesday evening.

Saunders added that the Toronto Police Services is not being “coy when it comes to comprising community safety” regarding this case.

“The evidence was presented to us at that particular moment it was very accurate,” he said. “In the courtroom the storylines will play out and will articulate exactly what happened, what we knew and what we did with it and based on that did we do the right thing or the wrong thing.”

“I’m comfortable with the investigation.”

Responding to public criticism surrounding the case, Saunders said officers have been displaced in the Church-Wellesley neighbourhood.

“I think that as those relationships develop those officers will have real-time issues and concerns that are raised by the community and work with the community to find out what the solutions are,” he said. “Once we’re in the community and we stay in the community for a long time we’ll have those oppourtunities.”

Police said Monday that they believe more victims will be identified and said DNA tests will be conducted on human remains found during a search of properties linked to McArthur over the past few weeks.

During a news conference Monday, police said investigators unearthed dismembered body parts belonging to at least three people in large planters at a Leaside property where McArthur stored tools for his landscaping business.

Any homeowners who hired McArthur for his landscaping services have been asked by police to contact investigators so their properties can be searched.

Police said so far, there are approximately 30 properties in Toronto that are now a part of the investigation.

Police continue to search McArthur’s apartment

Forensic officers continued to pore over McArthur’s apartment on Tuesday.

A forensic team was spotted coming in and out of his 19th floor apartment on Tuesday morning as investigators search for evidence in what they have described as an “unprecedented” case for Toronto police.

[A timeline of events in the Bruce McArthur case]

One resident of the apartment building, who told CP24 they live on the same floor as McArthur, said the 66-year-old was “very kind” and said hello to everyone.

“He’d smile at people. He’d help people out. He helped me once carry my bags from my car up to my home because we lived on the same floor,” the resident, who asked to remain anonymous, said.

Early one morning, the tenant said he heard something loud being tossed down the garbage chute and went out to check what was going on.

“I looked and I saw Bruce and I said to him, ‘Hey Bruce, what are you doing throwing out boulders or rocks outside in the garbage chute?’ I said, ‘Bruce, it’s two o’clock in the morning, you are waking us all up,’” the resident said.

“He turned around and he looked at me and there was something about his eyes that were very round and big, and he said to me… ‘I’m going to throw out my garbage whenever the eff I want to.’”