Detectives investigating the murders of two teenage girls in the 1980s had a breakthrough ‘penny drop’ moment when they realised the cases were linked, a documentary re-examining the case reveals.
Detective Chief Superintendent Charles Farquhar was tasked with investigating the killing of teenager Alison Day, who was found dead in the River Lea at Hackney Wick, north London, after going missing on December 29, 1985.
Farquhar had to fight to keep the case open despite the lack of forensic evidence or leads, defying the orders of his higher-ups, his son Simon Farquhar explains in Channel 5 documentary The Railway Killers, which airs tonight.
Farquhar’s decision to stand firm meant that when another girl, Maartje Tamboezer, 15, was found dead in Surrey in April 1986, the two police forces were able to pool their knowledge and eventually bring killer John Duffy to justice.
Duffy was eventually convicted of the two murders, as well as four rapes, in 1988 and sentenced to 30 years in prison.
Nine years later, he revealed he had an accomplice in David Malcahy, who was convicted of three murders and seven rapes and handed three life sentences. Duffy was later convicted of 17 additional rapes and admitted to killing a third woman.
Author Simon Farquhar revealed how his father, Charles Farquhar, pictured, fought for the case of Alison Day’s 1985 murder to remain open, which led to the arrest of the Railway Killers, John Duffy and David Mulcahy
Mulcahy and Duffy, pictured in their 20s, raped and killed women in North London and in the greater London area between 1982 and 1988, until Duffy was arrested in connection with the murder of 15-year-old Maartje Tamboezer
Alison Day, 19, pictured, went missing on 29 December 1985 in Hackney Wick. She was found dead in the canal weeks later
But the pair might have escaped justice had it not been for the tireless work of Farquhar, his son explained.
‘My dad had been in the Flying Squad for three years in North London and then he was moved to Romford in the murder squad,’ he said.
‘And he inherited two inquiries that were going on at the time, one of them was the disappearance and murder of Alison Day, and he was given the inquiry with instruction to basically close it down.
‘”We don’t have the resources and there just isn’t the evidence. Were never going to get anywhere”.
‘But what he actually did was, he went to the officers on the ground and asked them what they thought.
‘And they all said: “We want to give this another go, we haven’t had the chance to give this a proper go yet.
John Duffy, pictured, was identified due his particular blood type, which secreted blood cells into his semen, which was found on the body of Maartje Tamboezer
Tamboezer, 15, was found dead in April 1986 after going missing during a bide ride along the train tracks near her home of Horsley, Surrey
‘Eventually, there was a showdown about this and he said to his boss “you can close it down if you want to, but you can be the one who tells Mr and Mrs Day that we’re not going to look for their daughter’s killer anymore”.’
Alison was ambushed by Duffy and Malcahy while leaving Hackney Wick train station to go meet her boyfriend who was working late at a nearby print works.
The two men repeatedly raped her before strangling her using a ligature tightened with a piece of wood. This method of strangulation is unusual and would prove critical in cracking the case.
Alison’s body was found in the water, meaning any forensic evidence had been washed away.
Simon said: ‘On the surface, there just seem to be no evidence, this seemed to be a random attack which they couldn’t link to any crime. This wouldn’t lead anywhere.
‘There was no forensic evidence found on Alison at all, there was no eye-witness, you can see why it’s a hell of a task, a hell of a commitment. You can see why the easy option would have been to say “I think it’s going to remain unsolved”.’
A breakthrough came less than six months later in April 1986 when 15-year-old Maartje Tamboezer was found dead in Surrey.
Maartje, who came from a Dutch family, was ambushed along the train tracks in West Horsley in Surrey during a bike ride to the village, where she wanted to buy sweets for her classmates ahead of a school trip to her home country.
After the alarm was sounded, a search for Maartje began and she was found in the woodlands.
She had been strangled, repeatedly raped, and the perpetrators had tried to set her on fire to hide evidence.
Crucially, a piece of wood had been found next to her body. Farquhar had taken the decision to not release the detail about the piece of wood to the public, in order to have a way to screen for copycat murders.
The method of using a piece of wood as a tourniquet to tighten a ligature is extremely unusual, so it made it more likely that the two would be linked.
Farquhar, who was leading the inquiry into Alison Day’s murder, compared notes with Detective John Hurst, who was leading the inquiry into Maartje’s death.
‘My dad kept one vital piece of information from the press, always as a way to tell if there was a copycat or whatever,’ Simon said.
‘”The other thing, and we’ve never made this public, is that a tourniquet was used”,’ Simon said, re-enacting his father’s conversation with John Hurst.
‘And there was this silence on the phone. The penny dropped with Surrey that was what the mysterious piece of wood next to the body was.
‘They thought that it’d been used as an accelerator to burn the body. It wasn’t. It was used act fallen out of the knot that had been used to strangle Maartje. There was this pause, suddenly, and it quickly became obvious there was a connection.’
Another breakthrough in the case occurred when a witness called the police to say they had spotted two men and a young woman who fitted Alison’s description speaking in Hackney Wick.
The witness said they saw the men drag the woman off the road. This confirmed investigator’s suspicion that whoever had attacked Alison and Maartje had not acted alone.
From there, the investigative team drew a possible connection with a series of crimes happening in North London, where several women have been reporting rapes since 1982.
‘The link was formed between these attacks and the murder of Alison Day and of course, because of the ligatures, of Maartje Tamboezer,’ said Detective Inspector Mick Freeman.
In addition to the amazing detective work from the police forces on both Alison and Maartje’s cases, progress in technology led to other breakthroughs.
Mulcahy, pictured, was only trialed in 2000 when Duffy confessed he had been his accomplice. Mulcahy was sentenced to three life sentences and a minimum of 30 years behind bar at the Old Bailey
DNA evidence did not exist but investigators focused on blood groups in order to identify perpetrators.
While there was no forensic evidence in the case of Alison, police found that there were some forensic samples on Maartje’s body, and that her attacker had a A blood type and was what is known as a ‘secretor’, a man who secretes blood into his semen.
The investigation used a early version of HOLMES, the Home Office Large Major Enquiry System.
They cross referenced the sample found on Maartje’s body with their database of crimes reported in the London rapes cases, and found a victim who had been attacked in a similar fashion as Maartje and who had survived.
From there, the police started to look for a man with a A blood type who was on the police database, which they call the ‘Z man.’
They went through the list of these men one by one cross-referencing them with witness statement of physical descriptions and alibis until they came to John Duffy, a railway carpenter who was known to police for a serious assault on his wife.
Duffy stood trial first in 1988 and was sentenced to 30 years in prison. He remained tight-lipped on his accomplice until 1997, when he revealed he had been working in collaboration with his childhood friend David Mulcahy.
In 2001 Mucahy was convicted of the murders of Alison Day, Maartje Tamboezer and newlywed Anne Lock, 29 – as well as being convicted of seven rapes.
Police suspect their crimes date back to the 1970s.
The Railway Killers documentary airs tonight, tomorrow and Wednesday at 9pm on Channel 5 at 9pm.