Duffy was very
interested in martial arts. He trained with swords, knives,
a quarterstaff and a garotte, and was much taken with the
martial art of Zen Budo,
which he believed dictates: "Leave
no witnesses."
John Duffy with his wife Margaret Byrne, at a family wedding.
In 1982 Duffy was told
that he had a low sperm count witch would prevent him from
having a child. He vented his boiling frustrations on his
wife Margaret. Duffy liked to tie his wife up before having
sexual intercourse. He told her that it was her - not his -
fault that she had not become pregnant. The couple split up
twice. On one of her visits to his flat to pick up her mail,
Duffy raped her.
Duffy said that the
first murder haunted him. At night in his cell at Whitemoor
prison,
Cambridgeshire, he would snap awake - or lie for
hours in a sweat, obsessed by the memory.
John Duffy "the man with the laser eyes".
Police search
Another police search
Police evidence
Tourniquet made of Alison Day's blouse
Chief Superintendent John Hurst
John Hurst was the
first one who noted common factors between the murder
of Maartje Tamboezer
in 1986, and a rape that occurred the
previous year.
His insight made John Duffy a prime suspect.
Profiler Professor David Canter
It is largely due to
the groundbreaking work produced by Professor Canter
in the
"Railway murders"
case that Profiling has become the
respected and
trusted investigative tool it is today in the
UK.