Three cases remain before the U.S. Supreme Court. One was brought by St. Louis County prosecutors, who do not support Williams’ conviction or upcoming execution.

Marcellus Williams, a Missouri inmate on death row since 2001, will be executed as scheduled after his last clemency request was denied, his lawyer says.

Missouri is set to execute 55-year-old Marcellus Williams on Tuesday despite opposition from the state’s prosecuting attorney and the victim’s family.