A former Mattapan resident pleaded guilty Wednesday to voluntary manslaughter and weapons charges for his role in a 2003 slaying of another man in Dorchester.

Linrose Woodbine, 36, made the plea in Suffolk Superior Court less than a year after the state’s highest court had thrown out his first-degree murder conviction in the case. He was sentenced to 15 years in prison Wednesday, with credit for time served since his arrest nine years ago, Suffolk District Attorney Daniel F. Conley’s ­office said.