The Supreme Court of Canada will decide on Friday whether the acquittal of a Nova Scotia woman who tried to hire a hit man to kill her husband will stand in what some are calling one of the most important domestic abuse cases in decades.

Nicole Ryan, a high school teacher in southwestern Nova Scotia, was arrested in March 2008 and charged with counselling an undercover police officer to kill her husband, Michael Ryan.

She was acquitted of the charge two years later after the Nova Scotia Supreme Court accepted her argument that she thought she had no other way out of an abusive, 15-year marriage to a man who repeatedly threatened her and her daughter.

The Nova Scotia Court of Appeal described the marriage as a "reign of terror."

Both the trial judge in Digby and the Nova Scotia Court of Appeal in Halifax agreed that Ryan was under duress when she approached the undercover police officer, and so she couldn't be held criminally responsible for her actions.

The defence of duress

Duress applies when a person is forced to commit a criminal act because they have been the victim of violence, threats or other coercion.

The Crown appealed Ryan's acquittal to the Supreme Court of Canada arguing that the defence of duress was incorrectly applied in her case.

Now her fate rests with Canada's highest court, which heard arguments in June.

Friday's decision could help clarify laws surrounding domestic violence, and whether victims can be held criminally responsible for taking steps to protect themselves, and in Ryan's case, her daughter as well.

"The Supreme Court of Canada now has an opportunity to make a decision that doesn't leave women out anymore," said Kim Pate, national director of the Elizabeth Fry Society.

The organization, which assists women involved with the criminal justice system, intervened in Ryan's case before it reached the Supreme Court.

Pate said it was only after police and victims services failed to help her that Ryan tried to hire a hit man.

"I think the Supreme Court of Canada has a real opportunity to say, 'It is clear that women in this country will no longer be relegated to second-class status."

With files from Daniel Schwartz