26 May 1944 in Shepton Mallet Prison, Somerset.

Patricia Wylie, Killycolpy, County Tyrone

Pte William Harrison was the only American who was convicted of child murder in the UK during the Second World War.

"He clearly had mental health issues," Mr Freeburn says.

"He was diagnosed in April of 1943 with constitutional psychopathic state and inadequate personality along with hysteria and amnesia.

"However, a board found - even though at this point he had resorted to alcohol to cope - he had no definite mental illness and it was recommended that he be returned to duty."

Image copyright US Army JAG file Image caption Pte William Harrison was the only American who was convicted of child murder in the UK during the Second World War

In June of 1944 Harrison was subject to court martialfor going AWOL and inflicting injuries on himself. He was sentenced to six months hard labour which was due to end on Boxing Day 1944, but his station commander remitted it on 23 September.

Two days later, Harrison persuaded a reluctant member of the Wylie family to let seven-year-old Patricia accompany him to a shop to buy minerals and sweets.

But he later attacked and killed Patricia, whose body was found behind a haystack half a mile from their home in Killycolpy.

"You almost get the sense it could have been very easily avoided [if Harrison had not been released]. It was incredibly tragic," says Mr Freeburn.

While the Harrison case in particular is horrific, it should again be stressed that considering the sheer number of US military personnel who served in