On Friday, 15th August, 1975, Peter Sutcliffe had a night out in Halifax with his long time friend, Trevor Birdsall.
Sutcliffe and Birdsall had visited several pubs before settling in the Royal Oak public house which was in the town centre. In the bar Sutcliffe told Birdsall that he thought the pub was full of prostitutes.
Olive Smelt, who was definitely not a prostitute, was also in the Royal Oak public house that evening.
Olive was forty-six years old and was employed as an office cleaner. She was happily married with three children.
Olive had got to the pub just before closing, and after having a drink, arranged to go to a fish and chip shop close to her home in Boothtown, Halifax. She had planned to take a supper home to share with her husband.
At approximately 11.30 pm, Olive was dropped off in a lay-by close to the fish and chip shop.
Sutcliffe and Birdsall were driving when Sutcliffe pointed to Olive Smelt and said: "That is a prostitute we saw in the pub".
Sutcliffe stopped the car, and after picking up a hammer from beside the seat, disappeared down an alleyway. He caught up with Olive Smelt at 11.45pm and tried to start a conversation with her about the weather. As Olive walked past, Sutcliffe struck her twice on the back of the head with the hammer. As she was laying face down he pulled up her skirt and exposed her buttocks. He then used a knife to slash at the bottom of her back.
Sutcliffe was disturbed by headlights and fled the scene.
The attack on Olive Smelt was not linked to the Yorkshire Ripper series until June 1978.
Detective Superintendent Holland of the Western Crime Area established an incident room at Halifax for the purpose of the inquiry.