WILSON, N.C. — A man who admitted to killing his grandparents will spend the rest of his life in prison.

Justin Pelletier, 21, pleaded guilty to shooting William and Edna Brantley in March while the couple was in bed. The couple was found four days later, on March 20, each with at least two gunshot wounds, authorities said.

Pelletier's plea means he will avoid the death penalty.

Authorities said that it appeared the motive for the killings was money. Pelletier, who had lived with his grandparents for at least two years, needed money to supply a drug habit, they said.

After his arrest, investigators found William Brantley's car, which had Edna Brantley's purse in it and a .22-caliber rifle that Sheriff Wayne Gay believes was used to kill the victims.