He was arrested in January after an investigation into the disappearances of two men from a predominantly gay neighbourhood in downtown Toronto a year ago.
McArthur came under suspicion in September 2017 in connection with the disappearance of Kinsman, but police at first rejected suggestions that a serial killer was prowling Toronto's gay neighbourhood.
The remains of Soroush Mahmudi, 50, who was reported missing by his family in 2015, were also officially identified by authorities on Friday.
Sources said photographs of eight murder victims were found on McArthur's computer, but two have yet to be unidentified.
Kinsman's sisters said they searched for their brother for six months before police eventually charged McArthur in his death.
Police will announce today that alleged serial killer Bruce McArthur is facing additional charges, a source confirms to CP24. At the time, Idsinga only identified one set of body parts - those that belonged to Andrew Kinsman.
Toronto police detective Hank Idsinga said on Friday they believe Mr McArthur will face more charges.
December 8, 2017 - Police Chief Mark Saunders says the force will review its practices in missing persons investigations.
Idsinga says Navaratnam's remains - and those of five other people - were found in large planters at a residential property where 66-year-old McArthur worked as a landscaper.
McArthur is also charged with the premeditated murders of Majeed Kayhan, 58, 47-year-old Dean Lisowick, and Selim Esen, 44. After an excavation of the backyard did not lead to further discovery of human remains, Idsinga said the police investigation of the property may not yet be complete.
According to local media, police made a quick decision to enter McArthur's home and arrest him on January 18 when they saw a young man enter his flat.
McArthur is next set to appear in court via video on February 28.