Mother and wife Lydia Sherman laced food and drinks with arsenic, killing three husbands and all of her children. Young mother Paula Sims murdered her two young daughters, but let her son live due to her personal view that girls were unwanted. Under the influence of serious drugs, Velma Barfield played caretaker while secretly killing people with arsenic. Away from the drugs, she became the 'angel of death row' before being executed.