Alfred Leonard Cline was born on March 12, 1888, in Frederick, Kansas. He grew up in a small town where he experienced a typical childhood for the time. Not much is known about his family or early education. As he grew older, Cline became known for his charm and ability to win people over.

In Cline's adult life, he married several women, often those who were wealthy or held high social status. He had a way of convincing them to include him in their wills. This earned him a reputation in his community. His marriages were often short-lived. Despite being married multiple times, he faced issues with the law throughout his life.

Between 1930 and 1945, Cline allegedly engaged in a series of marriages to wealthy women, whom he persuaded to bequeath their assets to him. He would then reportedly serve them buttermilk laced with powerful sedatives, leading to their deaths, which were often attributed to natural causes such as heart failure. Cline's method involved taking his new wives on lavish honeymoons, during which he would administer the poisoned beverage. To eliminate evidence, he frequently arranged for the prompt cremation of their bodies. Through these actions, he is believed to have acquired over $82,000 from his victims.

Despite suspicions and investigations, concrete evidence linking Cline directly to the murders was insufficient for homicide charges. In 1946, he was convicted on multiple counts of forgery related to his fraudulent activities and sentenced to 126 years in Folsom State Prison. Cline died of a heart attack in prison on August 5, 1948.