The first execution in Missouri in over 2/12 years is set to take place tonight (Tuesday).
51 year old Russell Bucklew was convicted of a 1996 murder and rape and in April the U.S. Supreme court gave the go-ahead for him to be executed.
Bucklew suffers from a rare disease that causes blood-filled tumors in his head, neck and throat.
His attorney said in a clemency request that if one of the throat tumors bursts during his execution, Bucklew could suffer an excruciatingly painful death.
Human rights groups and death penalty opponents in Missouri are urging Governor Mike Parson to intervene.