Gary Leon Ridgeway is the Green River Killer. Ridgeway was interview back in the day and his DNA was taken. Years later when DNA tests were available his matched a victim(s), and he was arrested and confessed.
You can read all about in Green River Running Red by Ann Rule or Search for the Green River Killer by Smith and Guillian (sp).
Or here http://www.crimelibrary.com/serial_k...r/index_1.html