The stories of notorious killer Katherine Knight, an Australian who skinned and decapitated her errant lover, and Blanche Taylor-Moore, who poisoned her partner in hospital.

The cases of Belle Gunness, who murdered her victims to reap financial rewards, and a carer from Connecticut who turned a home for the elderly into a death parlour.

The case of 17th-century serial killer Erzsebet Bathory - a Hungarian aristocrat who is said to have murdered 600 of her servants in an attempt to achieve eternal youth.