Robert Lee Nelson, 22, pleaded guilty Monday to two counts of Murder in the stabbing deaths of Walter Swaner, 84, and his wife Mary, 80, at their home on Dixie Acres Drive in Dillon County in December of 2009.
Circuit Court Judge Steven John sentenced Nelson to 45 years in prison.
He was sentenced to 52 years in prison on those charges.
Nelson agreed to drop his appeal on his conviction last July as a part of his guilty plea in the murders, said Fourth Circuit Assistant Solicitor Kernard Redmond.
The Swaner's family says the killings were unimaginable and they continue to grieve for their loss.
"Mary and Walter did everything they could to help this teenager. And in return he killed them. Our family respectively ask the court not be lenient on this man," said Dorothy Fisher.
Nelson did yard work for the Swaner's from time to time. He is not eligible for parole.