8th March 1978 - The first letter to be received was postmarked "Sunderland 1.45pm 8th March 1978", and addressed to Mr. Oldfield. The author of the letter claimed to have committed the series of crimes and signed the letter "Jack The Ripper".

On the 6th February 1977 an exercise, known subsequently as the “Tracking Inquiry” was mounted to identify the vehicle which had left the tyre marks at the Irene Richardson murder scene.

As the 'Tracking Inquiry', which was started in connection with the Irene Richardson murder, was discontinued the hunt for a white Mark II Ford Cortina began. A nightwatchman saw a car draw away from the scene of the Maureen Long attack on the 10th July 1977 and described it as a white Mark II Ford Cortina.

The Chief Constable of West Yorkshire, Mr. Gregory, wrote to the Director of the Police Scientific Development Branch asking whether the Branch was able to offer any assistance in connection with the Yorkshire Ripper inquiry.

Following a request from Detective Chief Superintendent Domaille on On the 26th April 1978 it was agreed to arrange for the results of the vehicle observations in "red light" areas to be processed on the Police National Computer.

Observations on vehicles in notable "red light" areas had by this time been commenced in other Northern cities within and outside West Yorkshire so that possible leads might be available to investigating officers in the event of a further Ripper crime.

On 11th July 1977 the Chief Constable of West Yorkshire, Mr. Gregory, wrote to the Director of the Police Scientific Development Branch asking whether the Branch was able to offer any assistance in connection with the Yorkshire Ripper inquiry.

On the 25th April, 1978, following increasing concern within the West Yorkshire force that the administration of the series inquiry was being overwhelmed by the amount of information being recorded and the number of actions required to clear it, a special inquiry team under Detective Chief Superintendent Domaille was appointed to conduct an internal review of the investigation.

Jean Jordan was murdered in the Greater Manchester Police area on the 1st October 1977. Her body was found on a disused allotment in Chorlton-cum-Hardy on the 10th October, nine days after her death.

An unusual and curious feature of this case was that there was evidence that the killer had returned to the scene some eight days after the murder, stripped the body and inflicted further injuries including an attempt to decapitate it.