Montreal police have made one arrest in the Tricia Boisvert case, which is now being treated as a homicide.
"Different clues lead the investigators to think maybe it’s the second homicide on the Montreal island in 2014," said Const. Simon Delorme of the Montreal police.
Police said they consider 30-year-old Gatineau man Philippe Steele Morin a suspect in Boisvert's disappearance and possible murder, and are still looking for him.
Boisvert's body and her car are still missing after she went missing from her home on Notre-Dame Street West in Montreal's Southwest borough on Friday night, police said.
The car was spotted in Ottawa on Tuesday, according to an Ottawa police source. Investigators are continuing to search for her and Morin.
"We're looking for this man," Delorme said, referring to Morin.
Police say they believe Morin was the last person to see Boisvert.
Gatineau police say Morin has been wanted since July 16 on charges related to an alleged domestic assault as well as vehicle theft, mischief and breach of probation.
Police search for clues
On Wednesday, investigators combed Boisvert's home in Montreal's Southwest borough, searching for clues about her disappearance.
Delorme said forensic experts have been called in to find scientific evidence that could shed light on Boisvert's disappearance.
Police said it's possible Boisvert could be in the Ottawa or Gatineau region, where she's originally from.
Boisvert is five feet eight inches tall, weighs 140 pounds and has long, brown hair.
Police are also looking for her car, a black 2008 Pontiac G6 with the Quebec license plate 156-XQG.
Police are asking anyone who might have seen Morin, Boisvert or her car to call 911, or to call Montreal police at 514-393-1133.