It was suspected that she had killed four of her husbands, a brother-in-law, and her daughter by using arsenic poisoning derived from flypaper[1] in order to obtain life insurance money.

Robert Dooley subsequently fell ill and died of typhoid fever on October 12, 1915, leaving Keller as the sole survivor in the family.

[5] Shortly afterward, Keller's three-year-old daughter fell ill and died, prompting the McHaffles to move to Montana.

Twin Falls County Prosecutor Frank Stephan began an investigation and had the bodies of three of Lyda Keller's husbands, her four-year-old daughter, and her brother-in-law exhumed.

[9] She pleaded not guilty in court, but was convicted of using arsenic to murder her husbands and taking the money from their life insurance policies.

Following a six-week trial, Southard was convicted of second degree murder and sentenced to ten years to life in the Old Idaho State Penitentiary.

[9] She escaped from prison on May 4, 1931[10] and took up residence in Denver, Colorado, as a housekeeper for Harry Whitlock, whom she married in March 1932, but who ultimately assisted in her arrest in Topeka, Kansas, on July 31, 1932.