Ronald Gene Simmons Sr. (July 15, 1940 – June 25, 1990) was an American spree killer and former military serviceman who murdered 16 people, including 14 members of his own family, over a week in December 1987 in Arkansas. The killings, considered the deadliest case of familicide in United States history, occurred at his home near Dover and later at a nearby law office, convenience store, and workplace. Simmons served more than 20 years in the U.S. Navy and Air Force before retiring. He was convicted and sentenced to death, waived all appeals, and was executed by lethal injection in 1990, becoming the first person executed by that method in Arkansas.
Among the victims were his daughter, whom he had sexually abused, and the child he fathered with her.