ST. LOUIS (AP) — The execution of a Missouri man is off for Tuesday and appears unlikely to happen Wednesday, either.

The U.S. Supreme Court on Tuesday night granted a stay of execution for Ernest Lee Johnson, who was convicted of beating three people to death with a claw hammer. The case was sent back to the 8th U.S. Circuit Court of Appeals.

Johnson claims that the execution drug 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.

Missouri Department of Corrections spokesman Mike O’Connell sent media witnesses home for the night late Tuesday, saying it wasn’t clear when the appeals court would take up the case. O’Connell says there is no indication that the courts will resolve the matter before 6 p.m. Wednesday. If it isn’t resolved by then, a new execution date would have to be set.