Murders of Lesley Howell and Trevor Buchanan

On 18 May 1991, Lesley Howell (31) and Trevor Buchanan (32) were murdered in County Londonderry, Northern Ireland, in a staged double killing carried out by Howell's husband, Colin Howell, who sought to disguise their deaths as a suicide pact. At the time, Colin Howell had resumed an extra-marital affair with Buchanan’s wife, Hazel; in his later confession, he stated that the affair formed part of the circumstances leading to the killings.

Source: Wikipedia — Murders of Lesley Howell and Trevor Buchanan (CC BY-SA 4.0)