Missouri Gov. Mike Parson has declined to grant clemency to death row inmate Ernest Johnson, despite requests for mercy from the pope, two federal lawmakers and thousands of petition signers. Johnson was convicted of killing three convenience store workers during a closing-time robbery in 1994. He is scheduled to die by injection Tuesday at the state prison in Bonne Terre. Johnson’s attorney, Jeremy Weis, called the decision disappointing. He says executing Johnson would violate the Eighth Amendment to the U.S. Constitution, which prohibits executing intellectually disabled people.