Christopher Elvin Williams, 32,was arrested Monday nightfor first-degree murder and conspiracy to commit first-degree murder. He remainsin the Grainger County Jail.
Lee Anne Stansberry, 34, faces the same charges and was arrested earlier in the day.
Patrick's case was featured on 10 News as a Cold Case in 2007.
Investigators are not yet ready to go into details about how they finally identified the suspects.
Monday night, Melissa's mother and aunt told 10 News they are relieved and grateful to the detectives who have worked so hard on the case.