Alfred Andrew Knapp was born in 1863 in Terre Haute, Indiana, to Cyrus and Susannah Knapp. He was one of two children in a family with seemingly ordinary roots. However, Knapp’s adult life was defined by long stints in prison, his criminal behavior, specifically violent assaults against women, began years before any murder was committed.

Despite a violent past, Knapp attempted to present a different image later in life. He joined the Fourth Christian Church and became a member of the Christian Endeavor Society. People who encountered him described him as having quiet, unassuming manners.

By the early 1900s, he was living with his fourth wife in Indianapolis. His previous marriages had ended tragically, especially for his second and third wives. At the time of his arrest, Alfred had married again, this time to a woman named Anna May Gamble, just weeks after allegedly killing his third wife, Hannah Knapp.

Alfred Knapp's string of murders spanned from 1894 to 1902, with victims ranging from adult women to a young child. The first confirmed killing was on June 21, 1894, when he strangled Emma Littleman in a Cincinnati lumberyard. Just over a month later, he murdered Mary Eckert on August 1. Then, shockingly, on August 17, he strangled his second wife, Jennie Connors Knapp, on Liberty Street in Cincinnati.

In July 1896, Knapp killed a child named Ida Gebhard in Indianapolis. He later claimed he had assaulted and choked other young girls, suggesting a pattern of impulsive, violent behavior that may have involved even more victims.

His most infamous crime occurred on December 21, 1902, when he strangled his third wife, Hannah Goddard Knapp, in their Cincinnati home. After the murder, he boxed up her body and transported it two miles to the Great Miami River, where he dumped it. The same day, he acted completely unfazed, visiting his sister Sadie Wenzel and later reporting his wife as missing.

Soon after, Knapp moved back to Hamilton, Ohio, then relocated to Indianapolis. By January 2, 1903, he had met and married his fourth wife, Anna May Gamble, just over a month after killing Hannah.

Knapp was arrested on February 25, 1903, after suspicions grew around Hannah’s sudden disappearance. Once back in Hamilton, he confessed not only to killing Hannah but to four other murders. His confessions were candid, even boasting that he had randomly attacked and choked girls in the past.

The trial for Hannah Knapp’s murder began without her body as evidence. Despite weak physical evidence, public interest in the case surged. Knapp acted indifferent throughout the process, while his sister tried to defend him by claiming he was mentally unfit. On March 3, 1903, Hannah’s body was found floating near New Albany, Indiana, her jewelry confirming her identity.

Knapp was convicted on July 16, 1903, and sentenced to death. His quote following the conviction—"I suppose it is all off with me"—captured his cold, emotionless demeanor. A retrial was briefly granted due to a technical error involving the use of his confession in court, but the appeal failed. On August 19, 1904, Knapp was executed by electric chair in the Ohio Penitentiary. He refused to offer any last confessions.