It’s a grisly story: A husband and wife murdering their three young daughters, ages 19, 17 and 13, by drowning them, along with their stepmother. The couple was assisted by their 21-year-old son. All were found guilty of first-degree murder in Ontario, Canada. They were sentenced to life in prison.

Mohammad Shafia and his wife, Tooba Yahya, immigrated to Canada from Afghanistan in 2007. Being Muslims, they believe in Shariah law, which in some cases allows so-called “honor killings” — that is, if a family member deviates from strict Muslim teachings, other family members can execute them.