South Carolina is preparing to execute the third inmate to be put to death since September as the state goes through a backlog of prisoners who exhausted their appeals while the state couldn’t find lethal injection drugs. Marion Bowman Jr.’s execution is scheduled for 6 p.m. Friday at a Columbia prison. Bowman, 44, was convicted of murder in the shooting death of a friend whose burned body was found in the trunk of a car. Bowman has maintained his innocence since his arrest. His lawyers said he was convicted on the word of several friends and relatives who received…..