The State Law Enforcement Division said today 21-year-old Davorius Mack had been charged with four counts of threatening the life of a public official.
Mack is serving an 11-year sentence for the 2006 shooting death of a Rock Hill store clerk. Mack pleaded guilty to felonies including accessory after the fact to armed robbery and murder in the death of 69-year-old Ned Marshall, who was found shot in the chest and leg.
Mack started his sentence in 2007 at a maximum security prison in Pelzer. Prison officials say he has been convicted of more than 30 disciplinary infractions, including threatening to inflict harm and striking an employee.