Lyda Southard was born on October 16, 1892 in Keytesville, Missouri, sixty miles northeast of Kansas City and in the central flatlands of Missouri. Lyda Southard married Robert Dooley on March 17, 1912. The couple settled with his brother Ed Dooley on a ranch in Twin Falls, Idaho and had a daughter, Lorraine, in 1914. In 1915, Lorraine died unexpectedly, Lyda claimed, as a result of drinking water from a dirty well. Edward Dooley died soon afterward in August 1915; the cause of death was ruled ptomaine poisoning. Robert Dooley subsequently fell ill and died of typhoid fever on October 12, 1915, leaving Lyda as the sole survivor in the family. Lyda collected on the life insurance policies of each person shortly after their death. Within 2 years after Robert’s death Lyda met and married William G. Mchaffle. Shortly afterward, Lyda’s three-year-old daughter fell ill and died, prompting the McHaffles to move to Montana. A year later, McHaffle suddenly fell ill of what was thought to be influenza and died in Montana on October 1, 1918. The death certificate ruled the cause of death as influenza and diphtheria. In March 1919, she married Harlen C. Lewis, an automobile salesman from Billings, Montana. Within 4 months of their marriage, Lewis fell ill and died from complications of gastroenteritis. Lyda Southard married for a fourth time in Pocatello, Idaho, to Edward F. Meyer, a ranch foreman, in August 1920. He mysteriously fell ill of typhoid and died on September 7, 1920.

Twin Falls chemist Earl Dooley, a relative of Lyda’s first husband, began to study the deaths surrounding her. Along with a physician and another chemist, he soon discovered that Ed and Bob Dooley were murdered by arsenic poisoning. Twin Falls County Prosecutor Frank Stephan began investigation and began exhuming the bodies of three of Lyda’s husbands, Lyda’s 3-year-old daughter, and Lyda’s brother-in-law. Stephan discovered that some of the bodies contained traces of arsenic, while others were suspected of arsenic poisoning by how well the bodies were preserved, and found her motive in the records of the Idaho State Life Insurance company of Boise. All 4 of Lyda’s husbands had held a life insurance policy where they listed her as the beneficiary. Lyda Southard was able to collect over $7,000 over the years from the deaths of her first three husbands. She was found by law enforcement in Honolulu, married for the fifth time to Navy petty officer Paul Southard. Following extradition to Idaho, she was arraigned on June 11, 1921.

Following a six-week trial, she was convicted of second-degree murder and sentenced to ten years to life imprisonment in the Old Idaho State Penitentiary. Lyda Southard escaped from prison on May 4, 1931 and took up residence in Denver, Colorado as a housekeeper for Harry Whitlock, a man she married in March 1932 but who ultimately assisted in her arrest in Topeka, Kansas on July 31, 1932. She returned to the penitentiary in August 1932. She was released on probation in October 1941, and received a final pardon in 1942. Lyda was returned to Idaho to face murder charges on Meyer. In court she was found guilty of using arsenic to murder her husbands and then taking the insurance money, after pleading not guilty. She was sentenced to ten years to life in an Idaho prison. It was determined that her motive for murder was money, since she had taken out and collected on the life insurance policies of each of her dead husbands. Lyda Southard later died of a heart attack on February 5 of 1958 in Salt Lake City, Utah. Her body was interred at Sunset Memorial Park in Twin Falls, Idaho.