The U.S. Supreme Court put on hold the execution of a Missouri man at the last minute, sending the case back to an appeals court for further review.
 
Death row inmate Ernest Lee Johnson, who was convicted of beating three people to death with a claw hammer, was scheduled to die at 6 p.m. Tuesday at the Missouri state prison in Bonne Terre. But the Supreme Court on Tuesday night granted a stay while the 8th U.S. Circuit Court of Appeals considers whether a complaint from Johnson was properly dismissed.

Johnson, 55, claims that the execution drug Missouri uses could cause painful seizures because he still has part of a benign tumor in his brain, and surgery to remove the rest of the tumor in 2008 forced the removal of up to 20 percent of his brain tissue.

It wasn't immediately clear how quickly the appeals court might rule, but Mike O'Connell, a spokesman for the Missouri Department of Corrections, sent media witnesses who had already gathered Tuesday night for the execution home.

"There is no indication of any kind that this is going to be resolved tomorrow," O'Connell added.

In Missouri, the state has 24 hours — in this case, until 6 p.m. Wednesday — to fulfill the execution warrant or the execution has to be rescheduled.

A second appeal, to the Missouri Supreme Court, claims Johnson's life should be spared because he is mentally disabled.

The Missouri Attorney General's Office says both claims are without merit.