John Walker Turnbull

John Walker Turnbull (18 May 1958 – 27 September 1999), was a lance corporal in the British 4th Royal Tank Regiment. He was the husband of the late Marion Jane Turnbull and the father of Aaron John Turnbull. He committed suicide after murdering his wife and the man with whom she was having an affair.

He was born in Durham, England, to British parents Jack and Jenny Turnbull. He was an apprentice welder alongside his father in his early teens. In his late teen years, he joined the British Army, and served for nine years. He left the Army after his posting in Osnabrück, moving back to Kent with his wife and son, where he worked as a heavy goods vehicle driver. In 1996, he was involved in a severe road accident, in which a large truck attempting to avoid hitting an animal in the road collided with Turnbull's vehicle. He barely survived the impact but was pulled from under the truck resting on top of his vehicle by a passing road user. After a period in hospital and surgery in which titanium plates were attached to fractured and broken bones, he underwent physiotherapy to regain partial use of a wrist, arm, leg and ankle that were badly damaged. Further surgery was performed to replace the original plates with permanent ones. During this time, Turnbull became an avid supporter of the Shooters' Rights Campaign which sought to prevent the British ban on hand guns, which eventually took effect in 1997 after the 1996 Dunblane massacre.

After a period of recuperation, in 1998 Turnbull became the head of security at Valence School for disabled children, where he worked until 20 September 1999. It was known that he left his job after discovering a love affair between his wife and David Battle. On 26 September 1999, he arranged to meet with them both in the family home in Kemsing, Kent, where he killed both with a shotgun.

His son was staying with his grandparents at the time. Turnbull later died on 27 September 1999 from a self-inflicted gun shot wound to the head on a hill near his home in Durham.