Letter three is the second letter directly to Oldfield, the writer discussed press coverage with George in the first letter and again here,,it says "that bit about her being in hospital" and it seems an obvious reference to a bit in the paper.. Anyway this person was not messing around,, the first letters warned that he would kill an old one next,,even suggested where,,Manchester or Liverpool, after it was carried out the writer said "you should have took heed",,"I wasn't kidding".. The third letter brings another warning of resumed activities or work just eleven days before another girl was killed in Halifax.. After a gap of almost a year a warning arrived and eleven days later it came true.. On top of that the envelope was stained with oil which was also found on the girls body/wounds,, On top of that, rare blood type B secretor was detected on the envelope which linked with another girls death where the same rare blood type had been found.. On top of that there was the same rearrangement of garments a bite mark and bootprints which linked other murders and placed Preston 75 firmly into the series. There are three threats to kill in the letters and tape,, they all came true and forensics confirmed.. One might think the tape prediction seems a bit vague time-wise,, but you should consider this,, an unusual triangular weapon had been introduced in Halifax,, the predictions no longer needed to be precise, just using that triangular weapon again was all that was needed,, the cops would know it was him.. The weapon was used again and it linked positively with Halifax,,so,, in a way, the tape prediction was not needed, the triangular weapon did the talking for him, that the tape may have goaded and terrorised is true but the main thing it achieved was to introduce a NE voice and when that was done the killings stopped. The letters and tape are obviously from the killer but how could they ever have been sure that the voice belonged to the same man, that was always, just an assumption..!