Any realistic attempt to understand the Yorkshire Ripper letters and tape should try to imagine the position of the person who sent them and the feedback to the author at that time... Sequence of events etc,,, rebuild the case from his point of view... And what does he see when they include Preston,, and another girl who had not previously been considered one of the series.. (See my Yvonne Pearson folder for more on that)... What would the sender of those letters think of the above Police response... It is reasonable to assume he wanted his letters from Sunderland to be Public knowledge as he sent one to the Mirror,,, but they were kept secret at that time,, in fact the full content of the 1978 letters was not made known until after Sutty was convicted.. Apparently leaked to the author David Yallop..