On the afternoon of 25 September 1944, William Harrison, a US soldier stationed in Northern Ireland , visited the cottage of the Wylie family in Killycolpy, County Tyrone, and offered to buy treats for the children. He had visited before and was, if not a friend, at least known to the family. Mary Wylie let him take her seven-year-old daughter, Patricia, better known as Patsy, across the fields to the shops. Even for an era accustomed to war, what happened next was sickening. Harrison raped, beat and strangled Patsy. He left her body behind a haystack and went to the pub. He later confessed and was tried, convicted and executed. The crime entered Northern Ireland folk memory and US military records as a footnote to the second world war , a case that was harrowing but, at least, closed. More than eight decades later however, new research has shed fresh light on the story – and revealed that it did not end when the hangman pulled the lever.…