View source for The 'Sunderland Letters' - Yorkshire Ripper Inquiry

== 8th March 1978 ==

The first letter to be received was postmarked "Sunderland 1.45pm 8th March 1978", and addressed to [http://crimehub.co.uk/index.php?title=Assistant_Chief_Constable_Oldfield Mr. Oldfield].

The author of the letter claimed to have committed the series of crimes and signed the letter "Jack The Ripper".

== 13th March 1978 ==

A few days after the first letter, a similar letter was received by the Chief Editor of the "Daily Mirror” newspaper in Manchester. This  letter was postmarked "Sunderland 10am on 13th March 1978".

No immediate action was taken following the receipt of these letters although there was a suspicion that the writer’s familiarity with the crimes was more  than  that which could have been gleaned from a study of newspapers and television programmes about the Yorkshire Ripper series.

== 23rd March 1979 ==

On the 23rd March 1979 a further letter addressed to [http://crimehub.co.uk/index.php?title=Assistant_Chief_Constable_Oldfield Mr. Oldfield] was dispatched from Sunderland. The suspicion that the writer might indeed be the perpetrator of the crimes began to grow and was reinforced by two factors. First, the author of the letters went to an unusually high degree of trouble to ensure that no fingerprints were left on either the paper or the envelopes, and second, analysis of the saliva on the third envelope revealed that whoever had licked it was a secretor of blood group “B”. 

The last factor was considered to be especially significant because analysis of semen recovered from the body of Jean Harrison in Preston showed that the person responsible for that crime was also group “B” and a secretor and was thus within 6% of the total male population. This unhappy coincidence had two effects. First, it tended to confirm that the Harrison murder was part of the series and second, if Harrison was in the series, the  blood grouping pointed to the authenticity of the letters. The two propositions were however mutually dependent and, as events were to prove, both wrong.

== 1st May 1979 ==

On the 1st May, following the murder of Bank Clerk, [http://crimehub.co.uk/index.php?title=Josephine_Whitaker_-_Yorkshire_Ripper_Victim Josephine Whitaker], an entry in the murder log approved  the  practice of eliminating suspects on the basis of the handwriting from the three "Sunderland" letters.

== 18th June 1979 ==

On the 18th June 1979 a further envelope addressed to [http://crimehub.co.uk/index.php?title=Assistant_Chief_Constable_Oldfield Mr. Oldfield] was posted in Sunderland.

When opened it was found to contain a cassette tape, recorded by a man with an accent which a voice expert said belonged to a man who had lived within 5 miles of Sunderland for much of his life. On the tape there was a personal message to Mr. Oldfield about his failure to detect the series of crimes. 

The saliva on the envelope flap was quickly found to indicate a “B” secretor blood-group so linking it with the third letter and, as a result, with the Harrison murder.  Senior officers in West Yorkshire now appeared to be fully convinced that the author of the letters and the tape recording was indeed the man responsible for the crimes which they were investigating and they decided to attach top priority to this aspect which, they felt, would be bound to lead to  the detection of the Ripper crimes. 

In addition to the major internal  police effort it was decided  to  seek increasing assistance from members of the public in West Yorkshire and the North East of England in an attempt to identify the voice on the tape and the writing on the letters.  Accordingly, a press conference was arranged, although the impact of it was slightly dulled by the publication earlier of some relevant aspects in the "Yorkshire Evening Post". Details of the letters and  tape were given at the press conference, which was held on the 26th June 1979, and police inquiries thereafter concentrated on identifying a suspect who still lived in the North East of England or a suspect with origins in the North East who had subsequently moved to the West Yorkshire area. From this stage, existing lines of inquiry, some of which had already been suspended  because of the demands of the Whitaker investigation, began to attract even lower priority.