Tillie Klimek is a female serial killer thought to be responsible for as many as 6 deaths. She was convicted of the murder of her third husband, after her fourth husband became ill and police suspected that he was being poisoned. They tested her husband and discovered that there was indeed arsenic in his system, they then exhumed the body of her previous husbands, who were all found to have lethal levels of arsenic in their system when they died.
Klimek was also suspected in the murders of several relatives and neighbours who died suspiciously. She was sentenced to life imprisonment for the murder of her third husband.