Kingston, Ontario

Kingston, Ontario (CNN) -- A Canadian jury Sunday convicted three members of a family of Afghan immigrants of the "honor" murders of four female relatives whose bodies were found in an Ontario canal.

Mohammed Shafia, 58; his wife, Tooba Mohammad Yahya, 42; and their son, Hamed, 21, were found guilty of first-degree murder in the deaths of Shafia's three teenage daughters and his first wife in his polygamous marriage. Sunday's verdicts followed a three-month trial, in which jurors heard wiretaps of Shafia referring to his daughters as "whores" and ranting about their behavior.

All three were sentenced to life in prison immediately after their convictions, with no chance of parole for 25 years.

"This is a good day for Canadian justice. Our democratic society protects the rights of all," Gerard Laarhuis, the chief prosecutor in the case, told reporters outside the courthouse in Kingston. "It's a very bad day, because this jury found that four strong, vivacious and freedom-loving women were murdered by their own family."

At least one Shafia family supporter interrupted Laarhuis with shouts of "lies" and called the verdict a "miscarriage of justice." But others cheered the verdict as Laarhuis continued.

The three Shafia sisters -- Zainab, 19, Sahar, 17, and Geeti, 13 -- were found dead inside a car that plunged into the Rideau Canal in Kingston on June 30, 2009. Shafia's first wife, 50-year-old Rona Amir Mohammad, also died.

The verdicts came on the second day of deliberations for a seven-woman, five-man jury in Kingston, about 280 km (175 miles) west of the family's home in Montreal. There was no immediate comment from defense attorneys.

Prosecutors said the girls' father, mother and brother all plotted to kill the four women in an "honor" murder. Investigators claimed that hours of wiretapped conversations reveal a premeditated plan to punish rebellious, Westernized daughters and their permissive advocate, Rona.

Shafia and Yahya admitted on the stand that they were upset with Zainab for running off to marry a Pakistani man they hated, that Sahar wore revealing clothes and had secret boyfriends, and Geeti was failing in school and calling social workers to get her out of a home in turmoil.
'No faith on earth justifies this'

Prosecutors argued that under instructions from his father, Hamed Shafia used the family Lexus to ram the other family car carrying the women into the canal. The shattered headlight on the Lexus, they claim, matches the damage on the rear bumper of the family Nissan in which the women were found dead.

Investigators also believed the victims might have died before they hit the water, because they were unable to escape despite their seat belts being unbuckled and the car being submerged in just 7 feet of water.

In the three-month-long trial, Shafia testified, "My children did a lot of cruelty toward me," as he wept openly on the stand. He went on to say he believed his children "betrayed" him by dating and he did not hide his anger, saying a father would never expect that kind of behavior from this daughters.

In taking the stand, Shafia swore to tell the truth on the Quran and he again invoked the holy book to say Islam does not condone killing people to preserve a family's honor.

In a direct response to a question from prosecutor Laurie Lacelle, Shafia said, "To kill someone, you can't regain your respect and honor. Respected lady, you should know that. In our religion, a person who kills his wife or daughter, there is nothing more dishonorable. How is it possible that someone would do that to their children, respected lady?"

"You might do it," Lacelle calmly replied, "if you thought they were whores." Shafia had used that term in a conversation captured by wiretaps.

Investigators played hours of the wiretap recordings in court, alleging many conversations involving the three suspects prove they were plotting murder. In some of the most shocking conversations, Shafia launched into a rant about his daughters' behavior.

"I say to myself, 'You did well. Would they come back to life a hundred times, you should so the same again,'" he says. And in another played in court and translated from the Afghan language Dari, he says, "May the devil defecate on their graves! This is what a daughter should be? Would a daughter be such a whore?"

Shafia and his lawyers tried to explain that his shocking words are traditional expressions in Dari that should not be translated literally. But the jury also heard from an expert witness on honor murders -- a term CNN is using in the interest of clarity rather than the more common "honor killings" because the latter phrase does not properly describe the alleged crime.

That witness, University of Toronto professor Shahrzad Mojab, said that in some families, honor is worth more than life.

In an interview with CNN, Mojab said that many times, honor crimes are calculated acts that involve more than one family member.

"There is a very important difference between honor killing and violence against women in the form of domestic violence. It is plotted, it is premeditated." Mojab said.

"What we need to understand is that the male power and the male desire for the control of the woman's body and the woman's sexuality -- the honor resides in that sort of understanding and the ownership of women's body and sexuality," he said. "So when that is being presented in a way that is not acceptable to the social norm, then the only way the honor can be restored is by purifying that. And the purification is through blood."