A father, mother and their son, all convicted of first-degree murder in the deaths of four family members, have asked Ontario's highest court for new trials.
In documents filed with the Ontario Court of Appeal, Mohammad Shafia, his wife Tooba Yahya and their son Hamed argue, among other issues, that their trial judge should not have admitted "overwhelmingly prejudicial" evidence from an expert on so-called honour killings.
The three were each convicted in January 2012 of four counts of first-degree murder in the deaths of daughters Zainab, 19, Sahar, 17, and Geeti, 13, and Shafia's first wife in a polygamous marriage, 52-year-old Rona Amir Mohammad.
The victims' bodies were found on June 30, 2009, in a car at the bottom of the Rideau Canal in Kingston, Ont.
The Crown at the trial asserted the murders were committed after the girls "shamed" the family by dating and acting out, and Amir Mohammad was simply disposed of.
While testifying, Shafia and Yahya denied any responsibility for the deaths. Hamed's lawyer told the court that Hamed had told an undercover private investigator he was present when the car carrying the victims went into the canal and had witnessed a tragic accident, but didn't call police at the time.
The trial judge described the killings as being motivated by the Shafias' "twisted concept of honour."
In their 110-page submission to the appeal court that meticulously reviewed the details of the case, Shafia, his wife and his son argued through their lawyers that they were subjected to "cultural stereotyping" at their trial.
In particular, they took issue with the admission at trial of expert testimony on honour killings from Shahrzad Mojab, a professor at the University of Toronto.
"The appellants submit that Dr. Mojab's evidence was overwhelmingly prejudicial and should not have been admitted," their lawyers said.
"Her evidence invited the jury to improperly find that the appellants had a disposition to commit family homicide as a result of their cultural background and to reject their claim that they held a different set of cultural beliefs."
The lawyers went on to argue that the jury was invited to compare the events in the case with Mojab's anecdotal accounts of entirely unrelated murders to fit the case within the template of culturally inspired homicides.
They also argued that the trial judge did not properly assess the admissibility of certain hearsay statements made by the four female victims before their death, and did not instruct the jury properly on them.
"It was critical that the jurors be told how this evidence could and could not properly be used, even if this meant that the jury charge would be somewhat more complex," they said.
Additionally, the lawyers argued the trial judge erred by not providing sufficient direction to the jury regarding the Crown's theory that Yahya could be found guilty of murder on the basis that her alleged failure to protect her children from her husband made her causally responsible for their deaths.
Shafia, Yahya and Hamed have been in custody since their arrests on July 22, 2009, and will have to spend at least 25 years from that date behind bars before they can apply for full parole.
The family immigrated to Canada from Afghanistan and settled in Montreal, where Shafia was a successful businessman.
Their case made international headlines and triggered a post-9/11 criticism of Muslim culture.