Charges were dropped last week against Kamel Stewart, 21, in the killing of Christopher McLean, 28, according to the Scotland County District Attorney's Office.
The office says the state was unable to prove that Stewart did not act in self-defense.
McLean was shot and killed outside Greenfield Apartments in Laurinburg in August of 2011.
Stewart was charged with McLean's murder last March.
Stewart's mother Ann Stewart says her son stayed in jail for nearly six months before being released on bond.
She questions why police didn't review the case as one of self-defense from the beginning.