Peter Sutcliffe, also known as the Yorkshire Ripper, was caught on January 2, 1981, in Sheffield. He was pulled over by a probationary constable, Robert Hydes, who noticed that Sutcliffes car had false number plates. At the time, Sutcliffe had a sex worker named Olivia Reivers in his car. After being arrested, Sutcliffe claimed that he needed to go to the toilet and stashed a knife, hammer, and rope behind an oil storage tank. When he got to the station, he concealed another knife in the toilet cistern. The following day, Sergeant Robert Ring returned to where Sutcliffe was pulled over and discovered the weapons. After two days of intensive questioning and a search of his home, Sutcliffe finally admitted to the killings.