KINGSTON, Ontario (AP) — A jury on Sunday found three members of an Afghan family guilty of killing three teenage sisters and another woman in what the judge described as “cold-blooded, shameful murders” resulting from a “twisted concept of honor,” ending a case that shocked and riveted Canadians.

Prosecutors said the defendants allegedly killed the three teenage sisters because they dishonored the family by defying its disciplinarian rules on dress, dating, socializing and using the Internet.

The jury took 15 hours to find Mohammad Shafia, 58; his wife Tooba Yahya, 42; and their son Hamed, 21, each guilty of four counts of first-degree murder. First-degree murder carries an automatic life sentence with no chance of parole for 25 years.

After the verdict was read, the three defendants again declared their innocence in the killings of sisters Zainab, 19, Sahar 17, and Geeti, 13, as well as Rona Amir Mohammad, 52, Shafia’s childless first wife in a polygamous marriage.

Their bodies were found June 30, 2009, in a car submerged in a canal in Kingston, Ontario, where the family had stopped for the night on their way home to Montreal from Niagara Falls, Ontario.

The prosecution alleged it was a case of premeditated murder, staged to look like an accident after it was carried out.