After the execution of Byron Black on Aug. 5, witnesses are slated to speak at a news conference outside the prison.

Tennessee executed death row inmate Byron Black on Tuesday despite raised concerns about his implanted heart device, which could cause a "prolonged and torturous execution."

Tennessee is scheduled to execute death row inmate Byron Black on Tuesday morning despite concerns his heart implant will shock him repeatedly during the lethal injection. Black, 69, is one of the longest residents on the state's death row.