Photo: The Canadian Press

Protesters show their support for Cindy Gladue attend a rally along Edmonton's city streets.

UPDATE 6:55 a.m.

The Supreme Court of Canada says Ontario trucker Bradley Barton should be retried for manslaughter, but not murder, in the case of Cindy Gladue, who bled to death in the bathroom of his Edmonton motel room.

In a 4-3 decision today, the high court says evidence about sexual history was mishandled at the original trial that led to Barton's acquittal on a charge of first-degree murder.

Barton acknowledged hiring Cindy Gladue for sex in 2011 and claimed the severe injury to her vaginal wall that caused her death was an accident during rough but consensual activity.

The Crown argued that Barton intentionally wounded Gladue and was guilty of first-degree murder or, at the very least, manslaughter, because the 36-year-old Metis woman did not consent to the activity.

Barton was found not guilty by a jury that repeatedly heard references to Gladue as a "prostitute" and a "native," but the Alberta Court of Appeal set aside the acquittal and ordered a new trial for first-degree murder.

A majority of the Supreme Court says Barton's new trial should be restricted to the offence of manslaughter, as the procedural errors at the original trial did not taint the jury's finding on the question of murder.

ORIGINAL 5:42 a.m.

The Supreme Court is to rule today on the case of an Ontario trucker acquitted in the death of an Alberta woman in what could set a precedent in Canada's sexual assault laws.

Bradley Barton claimed that Cindy Gladue died after a night of consensual rough sex in an Edmonton motel in June 2011.

A jury found him not guilty of first-degree murder and manslaughter, after a trial in which Gladue was continuously referred to as a native prostitute and her preserved vaginal tissue was an exhibit.

The Crown appealed following nationwide protests and the Alberta Court of Appeal ordered a new trial.

The Appeal court ruled serious errors were made in the original trial and in the judge's charge to the jury about Barton's conduct and on sexual assault legislation pertaining to consent.

The Supreme Court heard arguments last October on several procedural matters, but could also decide for the first time whether an "objective likelihood of harm'' cancels out sexual consent.

The Alberta Crown, as well as attorneys general in other provinces, argued for such an addition to the law.

Barton's lawyer, Dino Bottos, has said it would be a big deal if the court agreed and noted the Crown brought up a consent versus harm argument on appeal — not at trial — so it shouldn't affect his client's case.

Barton testified that he hired Gladue for two nights of sex that included putting his fist in her vagina. When he woke up after the second night, he said, he found her dead in the tub and called 911.

Court heard Gladue had an 11-centimetre cut in her vagina and bled to death.

A medical examiner testified that the wound to Gladue's vaginal wall was likely to have been caused by a sharp object and, in a rare move, he used Gladue's preserved vaginal tissue as an exhibit.

Some interveners in the case said they believe Gladue didn't consent and noted the Metis mother of three deserved better at trial.