The U.S. Supreme Court denied convicted killer John Middleton's request for a stay of execution.  

Middleton was executed Wednesday for killing three people in remote northern Missouri in 1995.

The Supreme Court denied Middleton's earlier requests for a stay, so his attorneys filed another petition. This one is an emergency application seeking a one-hour reprieve.

Missouri Gov. Jay Nixon denied a clemency request.

The execution originally scheduled for 12:01 a.m. was  delayed all day by legal wrangling.