DNA on anonymous letter and on chewing gum convicts builder of killing ex in 1981

A builder has been found guilty of killing his ex-partner in 1981 after his DNA was found on an anonymous letter blaming another man for the killing.

Osmond Bell, 60, also left traces of DNA on chewing gum used to secure the door of a utility cupboard where he dumped the body of Nova Welsh after strangling her at her flat.