Trevor Birdsall was a friend of Peter Sutcliffe, the Yorkshire Ripper.
The attack on Olive Smelt
On the 15th August 1975 Trevor was with Peter Sutcliffe in a car in Boothtown, Halifax. Sutcliffe left Trevor in the car in order to carry out a brutal attack on Olive Smelt. Olive was brutally attacked with a hammer and sustained serious head injuries.
The anonymous letter to police
On the 26th November 1980 an anonymous letter was received at the Millgarth incident room. The letter, which was one of many being received at the time, suggested that a man called Peter Sutcliffe was the "Ripper". The author of this letter has since been identified as Trevor Birdsall a close friend of Peter Sutcliffe.