Executing the mentally ill Charles Singleton, a man who killed a store clerk in Arkansas, was sentenced to death in 1979, and then developed schizophrenia at some point after the trial. Inasmuch as the United States does not allow executions if a person cannot understand why he or she is being executed, state officials wanted Singleton to take medications to clear up his psychosis. After years of legal appeals, the U.S. Supreme Court ruled in 2003 that Singleton was by then taking medications voluntarily, and he was executed by lethal injection in 2004.