On Friday 2nd January 1981, Sergeant Robert Ring was on night duty with probationer constable PC Robert Hydes when they spotted a car in the driveway of the Light Trades House in Sheffield. Sutcliffe was in the car with prostitute Olivia Reivers who was well known to the police.
Upon closer inspection the Rover was displaying false number plates which actually belonged to a Skoda saloon.
Sutcliffe and Reivers were both arrested on suspicion of theft. Prior to being put into the police car Sutcliffe went to urinate a short distance away from the officers. Whilst there he hid a hammer and knife. On getting to the police station Sutcliffe hid another knife in the toilet cistern.
When Sergeant Ring signed on for duty the next evening Peter Sutcliffe was still in custody being questioned. It was at this point that Ring remembered Sutcliffe being out of sight whilst he 'urinated'.
Ring returned to the arrest site and discovered the hammer and knife. He reported this to the station. Sutcliffe admitted to being the Yorkshire Ripper whilst in custody.