Taggart (1983)

S14E2 Out of Bounds

A schoolmaster is brutally killed with a cricket bat by an unidentified attacker. Six decades later, students discover the remains during a cross-country run. Douglas Flemming recognizes the bones as belonging to Friedrich Zwanziger, a stern disciplinarian who vanished while on a beetle-collecting expedition. As the investigation unfolds, McVitie reveals that he serves on the board of governors.