WaPo Duisburg S03E08 - Verdammt lang her

A fisherman disappears without a trace at a campsite on the Rhine. While the police search for him, Carsten Heinrich discovers the body of a man who was convicted of murder ten years ago and recently released. It turns out that the missing angler and the body are the same person. While investigating the old case, they find evidence that the man was innocent and was murdered because he was on the trail of the real killer.