By Tim Lambert
The Shy Schoolgirl
In 1986 Maartje Tamboezer was a 15 year old Dutch schoolgirl living in England. She was the victim of a horrific murder between the villages of West and East Horsley, near Guildford in Surrey, England.
Maartje was born on 22 March 1971 in the Netherlands. She was the oldest of three sisters. Her father worked for a Dutch oil company, and in 1986 he was stationed in England. Maartje and her family lived in a rented house in the affluent village of West Horsley near Guildford in Surrey.
Maartje went to a school in Cobham, Surrey where she was intelligent and studious. Maartje was described as a shy or quiet girl, but she was very pleasant. Her friends called her Marty. She was pretty and she had a boyfriend.
Maarjte Tamboezer
The Murder
Meanwhile, in 1982 two evil men, John Duffy and David Mulcahy had begun a series of appalling rapes near railway stations in London. Duffy was born in November 1958 and Mulcahy was born in May 1959. They met at school were they became best friends. In 1982 the two began raping women.
However, they eventually graduated from rape to murder. It seems that Mulcahy was no longer aroused by rape. He wanted the thrill of killing. The first murder victim was a 19-year-old woman named Alison Day. She was strangled in East London on 29 December 1985.
Maartje Tamboezer was raped and murdered on 17 April 1986. It was a sadistic murder. Mulcahy and Duffy travelled to the village of East Worsley in Sussex and waited on a path by a railway line that led past neighbouring West Worsley.
Maartje was due to go on a trip to the Netherlands the next day. In the afternoon, after school she went to buy some English sweets to take with her. At first she planned to go to a shop in West Worsley but she was told that a shop in nearby East Horsley had a better selection. So she set off on her bike, wearing a blue jacket and trousers. She was wearing mittens and her purse hung on the handlebars of her bike.
Maartje cycled along the track where Mulcahy and Duffy were waiting. They watched her pass but at first they did not attack her because the area was not clear. Mulcahy realised she would probably come back the same way so he strung fishing line across the path. When she returned Maarjte saw the string in time and stopped her bike.
The murderers jumped out of their hiding place. David Mulcahy pulled Maartje off her bike and ordered her to be quiet. John Duffy held her by the collar and forced her at knifepoint to walk across a field towards Lollesworth Wood. Mulcahy wheeled her bike along then left it in the woods. At that point, Maartje screamed. Mulcahy walked over to her and hit her with across the face with the back of his hand. He ordered her to be quiet and not to look at him. Still wearing mittens her hands were tied by the thumbs.
They walked Maartje by a long and roundabout route to the site where she was raped. She was probably forced to walk a long way to prolong her terror. It was mental cruelty.
When they stopped Mulcahy went to be a lookout, while Duffy raped Maartje. When she tried to stop Duffy removing her trousers Mulcahy came over and threatened her. John Duffy then raped her.
After the rape Duffy grabbed Maartje by the arm and walked her over to Mulcahy. Both men forced Maartje into a wood. According to Duffy Maartje started speaking again. Mulcahy became angry and shouted ‘You are looking at me again. I told you I would hurt you! Without warning he hit her over the head with a piece of flint. She was knocked unconscious’.
Duffy also said ‘‘He was becoming very aggressive – hyper, shouting at the girl, He then raised his fists and hit the girl’.
‘She crumpled to the floor. She was struck on the head, at the side. It was a swinging blow. I noticed he had a rock in his hand, or a stone. She just crumpled up and fell on the floor. I believe she was unconscious.’
John Duffy then strangled the child with a tourniquet. Duffy said Mulcahy ripped off Maartje’s belt and looped it around her throat, telling him: ‘I did the last one, you’ll do this one’.
‘He passed me the belt. It had a piece of stick through it which was twisted and he gave it to me in my hand,’ Duffy claimed. ‘I actually started twisting it while David turned away. I think I just got caught up in it. It is very difficult to explain. I just continued twisting until she was dead.’ Afterwards Mulcahy slapped Duffy on the back and told him ‘you done good’.
Mulcahy told Duffy to go home while he returned to destroy evidence. He wiped fingerprints off the belt and the rock. He also set Maartje’s body alight, using burning tissues hoping to destroy forensic evidence. Parts of her body were burned.
Meanwhile a man walking along the path by the railway saw the string tied across it. Thinking it was a prank by children he untied one end of it and threw it over the fence dividing the path from the railway.
By evening Maartje’s parents were very worried and they called the police. At about 10.30 pm her bike was found but there was no sign of her. It was dark so the search was called off till the following morning.
The search began at dawn the next day. Shortly afterwards, two men who were ferreting to control the local rabbit population saw what they thought was a blue fertiliser bag among bluebells in Lollesworth wood. At about 8.15 am they met police, who asked them if they had seen any sign of the missing girl. The men said they had seen what they thought was a blue fertiliser bag. They showed the police where it was. It turned out to be the body of Maartje Tamboezer.
Detective Superintendent John Hurst said ‘It was probably the worst killing I’d come across in my career. She had been savagely raped, subjected to brutal head injuries and strangled. The murderer had tried to destroy the body by burning it. And it was so horrendous that everybody was absolutely devastated and upset by what they saw’.
Maartje’s body was scanned with a laser for fingerprints. Afterwards a post mortem was carried out by Dr Roger Ainsworth. It showed Maartje had lacerations on her head caused by a blunt object (according to Duffy, Mulcahy hit her with a stone). She was knocked unconscious. However the cause of death was asphyxiation. Maartje Tamboezer was cremated on 25 July 1986 and her family moved back to the Netherlands.
Operation Bluebell
Poor Maartje was found lying in a wood surrounded by bluebells so the investigation was called Operation Bluebell. Unfortunately DNA evidence was not available in 1986 but from semen stains on Maartje’s clothes police were able to say it came from a man with group A blood. However, the police could not match it any one individual.
The police found another clue: Maartje’s hands had been bound with an unusual type of string. The factory that made it narrowed it down to a batch made in 1982. Later, the police found a matching ball of string in Duffy’s parents house.
Unfortunately Duffy and Mulcahy struck again. On 18 May 1986 they raped and strangled a young woman, Anne Lock near a railway line north of London. Her body was not found until July 1986.
But the net was closing in on John Duffy. The police gathered more and more evidence against him. They also asked psychologist Professor David Canter to draw up a psychological profile of the offender. Duffy was arrested in November 1986. However, at that time there was insufficient evidence to arrest David Mulcahy and he escaped justice for several years.
John Duffy
In February 1988 John Duffy was convicted of two murders, of Alison Day and Maartje Tamboezer. (The judge ruled that there was insufficient evidence to convict him of the murder of Mrs Anne Lock, although years later Duffy admitted his guilt). He was also convicted of four rapes.
The judge called Duffy ‘a predatory animal’. He said: ‘the wickedness and beastliness of the murders committed on those two very young girls hardly bears description’. They were ‘as appalling as anything I have come across’.
He also said ‘You cut short those two young lives and blighted the lives of all the families of those young girls’. He sentenced John Duffy to life imprisonment with a minimum term of 30 years. The Home Secretary later changed it to a whole life tariff.
After Duffy was arrested Mulcahy stopped raping and killing women. (Although in 1990 he was convicted of assaulting his son and he was fined). However, in 1998, while in prison John Duffy claimed he was suffering from nightmares. He was referred to a psychiatrist, Dr Jennifer Cutler and for the first time he admitted he had an accomplice in the rapes and murders – one who had never been caught. Duffy eventually confessed his crimes to the police, including the murder of Maartje Tamboezer.
Duffy gave a horrifying description of how he strangled the child with a torniquet. Detective Leslie Bolland said ‘It was the most chilling, frightening thing I’ve ever come across in twenty-eight years’. Fortunately, Duffy also agreed to give evidence against David Mulcahy.
David Mulcahy
The police gathered other evidence against Mulcahy and he was arrested in February 1999. In February 2001 he was convicted of three murders, Alison Day, Maartje Tamboezer and Anne Lock. He was also convicted of seven rapes.
The judge told Mulcahy ‘These were sadistic killings. Of the two of you, I have no doubt that it was you who gained gratification from killing. These were acts of desolating wickedness in which you descended to the depths of depravity in carrying them out.’
He sentenced David Mulcahy to life imprisonment for the murders with a minimum term of 30 years. He was also sentenced to 24 years for each of the rapes. He was not given a whole life tariff because the Home Secretary by the time his case was reviewed the Home Secretary had lost his power to set life sentence prisoner’s tariffs. However, it is unlikely either of the two fiends will ever be released.
A field between East and West Horsley
A book about the Railway Killers, Duffy and Mulcahy, called A Dangerous Place by Simon Farquhar was published by History Press. It is available on Amazon.
The Railway Murders (YouTube).
John Duffy and David Mulcahy Court News UK
A History of East and West Horsley
Last Revised 2026