On 31 January 1978, Sutcliffe killed Elena "Helen" Rytka, an 18-year-old prostitute from Huddersfield, striking her on the head five times as she exited his vehicle at Garrards timber yard before stripping most of the clothes from her body, although her bra and polo-neck jumper were positioned above her breasts. Rytka was then sexually assaulted as she lay on the ground. She was the only one of his victims that he had sexual intercourse with. After Rytka staggered to her feet, Sutcliffe again struck her on the back of the head with a hammer a number of times before retrieving a knife from his vehicle and stabbing her several times through the heart and lungs. Her body was found three days later behind a stack of timber, placed under a sheet of asbestos, beneath the railway arches of the timber yard.  Sutcliffe said of Rytka while in police custody in 1981: "I had the urge to kill any woman. The urge inside me to kill girls was now practically uncontrollable.