Missouri Attorney General Chris Koster is asking an appeals court to overturn a stay of execution for John Middleton, scheduled to die early Wednesday for killing three people in northern Missouri in 1995. U.S. District Judge Catherine Perry ruled Tuesday that there was enough question about Middleton's sanity that a hearing should take place. The U.S. Constitution prohibits executing the mentally ill. Koster asked the 8th U.S. Circuit Court of Appeals to vacate the stay. Middleton was a methamphetamine dealer convicted of killing Randy "Happy" Hamilton, Stacey Hodge and Alfred Pinegar because he feared they would go to police. In a separate ruling late Monday, the appeals court refused to halt the execution on Middleton's claim that he is innocent. Middleton's attorneys appealed that case to the Supreme Court.