From Wikipedia:

Lyda Southard, also known as Lyda Anna Mae Trueblood, was an American female suspected serial killer. It was suspected that she had killed her four husbands, a brother-in-law, and her daughter by using arsenic poisoning derived from flypaper in order to obtain life insurance money.

• Born: October 16, 1892, Keytesville, MO
• Died: February 5, 1958, Salt Lake City, UT
• State(s): Idaho, Montana
• Victims: 6
• Other names: "Flypaper Lyda"; "The Black Widow"
• Criminal penalty: 10 years to life imprisonment
• Span of crimes: 1915–1920