Ronald Gene Simmons Sr. (July 15, 1940 – June 25, 1990) was an American mass murderer and spree killer who killed 16 people over a week-long period in Arkansas in 1987. As a retired military serviceman, Simmons murdered fourteen members of his family, including a daughter he had sexually abused and the child he had fathered with her, as well as a former co-worker, and a stranger; he also wounded four others. He is the worst mass murderer in Arkansas history.