Missouri has executed an inmate convicted of murder in the 1993 deaths of a farming couple.

Missouri Department of Corrections spokesman Mike O'Connell says William Rousan was declared dead at 12:10 a.m. Wednesday. He was put to death by lethal injection at the Eastern Reception, Diagnostic and Correctional Center in Bonne Terre.

Prosecutors say Rousan, his teenage son Brent Rousan and William's brother Robert Rousan murdered Charlie and Grace Lewis on Sept. 21, 1993 as part of a plot to steal two of the couple's cows.

Brent Rousan is serving life in prison without parole. Robert Rousan served seven years after pleading guilty to second-degree murder.