Anthony Patterson, 21, pleaded guilty to kidnapping and killing Tia Carroway in 2002. Frances Perkins, Carroway's mother, directed her emotional outburst toward Patterson.
"I don't understand just why did you do this to my baby? Why? What did she do to you?" Perkins said.
Prosecutors said Patterson and Naeem Mahmoud kidnapped the Durham Regional Hospital nurse while she was getting lunch for her co-workers.
Prosecutors said both men took Carroway to an abandoned area and Mahmoud later shot her in the back of the head. They said both men wanted her car.
Rodney Perkins, Carroway's stepfather, told the judge about her smile and how they miss it every day.
"We're hurting bad. It will never go away. Today or tomorrow, it's never going to go away," he said.
"This was a senseless, cold-blooded killing. For what reason? Why? What's the point? There is no point," Judge Abraham Jones said.
Patterson will spend the rest of his life in prison.
Mahmoud's trial is set to begin in December. If convicted, he could get the death penalty.