Hello Sleuthers,
Longtime lurker - never felt I had anything significant to add in any thread that wasn't already said, and even here not sure my two cents are warranted. That aside, I love the community and love the work being done here.
As a lifelong local to the area, I took an interest in many of these sadly unsolved cases of missing and murdered women, most of whom seem to have had links to the the Byward Market and Vanier areas and to drug use and/or the sex trade (though not all of course, more on these below) spanning from 1988 to this year. It's quite sad to see that nothing more has really come of any of these cases, or LE's suggestion of a serial killer still at large, which even after Leduc's incarceration, I would agree with.
I've only just returned to my research in earnest in the last few days and there have been a few new cases I find interesting on this subject, though not definitely related.
The body of Annie Pootoogook, 46, wonderful and troubled Inuit artist, was found in the Rideau River in September 2016. After achieving quite a degree of fame in the art world, she fell on very hard times and was living on the streets of Ottawa, lower town in particular, of which the Byward Market and Vanier are parts of. She was very difficult to locate before her death and police say her whereabouts were difficult to trace. Though not treating this as a homicide, police considered the circumstances around her death "suspicious" and it at least was in the hands of the Major Crimes Unit. As far as I can see no developments have been mentioned since.
Ottawa police investigating ‘suspicious’ death of Inuit artist Annie Pootoogook
Then, in April 2017, 39 year old Mary Papatsie went missing, a then streetwalking Aboriginal mother of ten, last seen on Montreal Road in Vanier. Her disappearance wasn't reported for five weeks. She had been known to live both on the streets of Vanier and in nearby Lower Town shelters. Her apparent haunt was the Jean Coutu drugstore on the West end of Montreal Rd. Claimed to have been seen a month later on the same street with a "young clean cut male", though unconfirmed. Prior to living in Vanier, she was tied to a few fixed addresses before leaving her last place for fear it was haunted. Foul play isn't necessarily suspected, though like Annie, her case is with the MCU.
http://www.cbc.ca/news/canada/ottawa/mary-papatsie-major-crimes-unit-1.4209491
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Though the police haven't disclosed much of anything on their serial suspicions, the unsolved cases with IMO legitimate similarities are:
Melinda Sheppitt, 1990
Sophie Filion, 1993
Amy Paul, 2013
Caucasian females, all tied to the Lower Town sex trade, all found in unrelated spots. I need to reread some articles on them to confirm and i may be completely incorrect, but my original notes mention nothing about them showing signs of sexual assault.