Bruce McArthur, 67, faces eight counts of first-degree murder and has a court hearing scheduled for Tuesday morning.
According to court documents, police found a bracelet belonging to Navaratnam in McArthur's bedroom during their investigation.
Who were McArthur's eight victims?
McArthur is facing eight counts of first-degree murder in the deaths of Selim Esen, Andrew Kinsman, Majeed Kayhan, Dean Lisowick, Soroush Mahmudi, Skandaraj Navaratnam, Abdulbasir Faizi, and Kirushna Kanagaratnam.
Police found an "abduction kit" in his home, which included syringes, duct tape, zip ties, and gloves.
McArthur also kept souvenirs to remember his victims by, including jewelry.
Prosecutor Michael Cantlon said the cases ranging from 2010 to 2017 involved sexual assault or forcible confinement and said the bodies were hidden and dismembered.
"But there is also confusion and questions as to why", he said. The term is typically used to suggest a body has been repositioned for a specific goal, such as hampering an investigation. The remains of an eighth man were found in a nearby ravine.
Karen Fraser, one of the home's owners, said she can't reconcile the energetic, enthusiastic man who worked on her property with the killer he turned out to be.
"This is something you'd want the world to know", he said. "This is someone else entirely".
Lisowick was McArthur's sixth victim, but unlike the others killed by McArthur, he was never reported missing to police.
McArthur will likely have the mandatory minimum of life imprisonment and be eligible for parole in 25 years, according to University of Ottawa Faculty of Law assistant professor, Kyle Kirkup.
"My thoughts are with the victims of these crimes, their friends and families, an LGBTQ community that remains shaken and hurt by this tragedy, and a community at large that grieves with them". "The fact that it remained unknown and unseen for so many years is its own inconceivable tragedy".
Alliance for South Asian AIDS Prevention Director Haran Vijayanathan, who has been speaking on behalf of many victims' families since his arrest, said that the guilty plea has been good for "closure".
"If there were mistakes made or lessons learned, absolutely we should learn from them", he said. An initial police task force in 2012 didn't lead to an arrest.
April 2014 - Police close Project Houston, saying none of their findings would classify anyone as a suspect of a criminal offence.
After 49-year-old LGBQT activist and former Toronto bartender Andrew Kinsman went missing, however, police revived the investigation.
Toronto police Det. David Dickinson said police continue to investigate the case.
December 8, 2017 - Police Chief Mark Saunders says the force will review its practices in missing persons investigations.
Forensic officers scoured McArthur's apartment for four months, moving centimetre by centimetre through the residence with the belief it was an alleged murder scene.
Numerous victims, although not all, were from the Gay Village, a neighbourhood in Toronto known for its predominantly gay population.