Zatoon Bibi. When Tanveer Iqbal's body was discovered in the boot of his car, Zatoon Bibi, her husband and 15-year-old son were arrested for his murder. Why did this family kill?
Virginia Vertetis. When Patrick Gilhuley was shot dead by his partner in 2014, she claimed it was self-defence, but her ex-husbands provided evidence of her violent past.
Kelly and Jason Cochran formed a killer husband and wife team - but then she turned on him. How many lives did she take before she was caught?
When Mike Williams left to go hunting one morning, he didn't know he was leaving forever. It would take nearly 20 years to find the killer: his wife, Denise.