The story of Erzsebet Bathory, a 17th-century Hungarian noblewoman, remains one of history’s most chilling—a tale alleging the murder of some six hundred of her servants as she sought to prolong her life indefinitely.

The stories of Belle Gunness, notorious for murdering those within her grasp to claim their fortunes, and a caregiver in Connecticut who transformed a nursing home into a place of quiet deaths, stand as chilling examples.

The cases of Katherine Knight, an Australian woman known for skinning and beheading her former boyfriend, and Blanche Taylor-Moore, who administered poison to her partner while he was hospitalized, remain chillingly unforgettable.