Investigators said they were trying to determine whether Shawn Cameron Lamb can be linked to other cases involving women who have been killed or have disappeared in the area, the Winnipeg Sun reported.
"I think it would be foolish to say there are no other victims out there," Police Chief Keith McCaskill said. "We don't know."
Lamb was arrested Thursday on a rape charge. The same day, a body, believed to be that of 18-year-old Lorna Blacksmith, was found near an apartment where he used to live.
Blacksmith was reported missing in January. The other alleged victims are Tanya Jane Nepinak, 31, who vanished in September and whose body has not been found, and Carolyn Sinclair, 25, whose body was discovered in March, three months after she was reported missing.
Lamb faces three counts of second-degree murder. The charges were a shock for the Blacksmith and Nepinak families because the women had been listed as missing.
"There's a lot of emotion, a lot of grief," Cross Lake First Nation Chief Garrison Settee told the Sun by telephone as members of Blacksmith's family wept. "We never gave up hope as a community. We kept praying we would find her alive."
Police said Lamb is a drifter who has spent much of his adult life in prison and has 100 convictions.