698
edits
Changes
no edit summary
== 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.