A Georgia prison guard was ambushed from behind and stabbed to death by an inmate with a homemade weapon on Sunday, the Georgia Department of Corrections said in a news release. Robert Clark, 42, was escorting two inmates from a dining hall when Layton Lester—a convicted murderer serving a life sentence for a 2007 killing and armed robbery—attacked him from behind. Another inmate tried to save Clark and sustained non-life-threatening injuries that sent him to the hospital, officials said. Clark had worked at Smith State Prison in Glennville—a rural town about 60 miles west of Savannah—for just six months before his slaying. “The entire GDC team is mourning the loss of one of our own and we collectively express our deepest condolences to Officer Clark’s family and friends,” Corrections Commissioner Tyrone Oliver said in a statement. Lester is facing charges for Clark’s death and for the assault of his fellow inmate.