On 23rd March 1988, Debbie Linsley said goodbye to her parents and drove to Petts Wood railway station with her brother, Gordon.
Debbie, 26, worked in Edinburgh but had been attending a management course in London. Her parents lived only 15 miles or so from London, so it was a good chance to have a family get-together, particularly as Debbie was going to be a bridesmaid at her brother's wedding in two weeks time.
Gordon dropped off Debbie at the station and she caught the 14.16 Orpington to London Victoria train.
In those days, many of the train carriages had no corridors. Instead, they were divided into compartments. Within each compartment, the seats faced each other along its width and there was a slam door on either side.
If you were travelling on your own at a quiet time of the day, you ran the risk of being in dubious company at some point in your journey.
Some six minutes away from London Victoria station, Debbie's train stopped at Brixton to pick up passengers. In that final six minutes between Brixton and London Victoria, Debbie was stabbed eleven times in a frenzied attack. She put up strong resistance and managed to injure her attacker. However, she died from a stab wound to the heart.
Debbie's body wasn't discovered until ten minutes after the train arrived at London Victoria. Her attacker was long gone. At that time, there was no CCTV to record the passengers leaving the train.
The police investigation was thorough but the murderer has never been caught. The murder weapon has also never been recovered.
But the killer did leave a small sample of his blood at the scene. Although DNA profiling was not in use in 1988, the case has been subject to periodic reviews. As a result, the new investigations have taken full advantage of the latest techniques in DNA profiling. Finally, the scientists were able to generate a full DNA profile of the crime scene blood.
But the killer's DNA profile isn't on the National DNA Database.
Investigators are convinced that Debbie did not know her killer. They also discount the 'known killer' theory. This is because a person like Debbie's killer would surely have committed other crimes. If so, he would more than likely have been arrested for some of them and had a mouth swab taken for DNA profiling.
Maybe the killer is dead.
But 25 years after Debbie's murder, another cold case review is taking place. This time the investigators propose using Familial DNA Searching. Instead of searching the National DNA Database for a profile that matches the crime scene profile, scientists will search for relatives of the offender who may be on the Database.
One argument for its use is that criminality tends to run in families. Another argument is that it is a way of keeping the investigation going.
Familial DNA Searching was developed in 2002 by the Forensic Science Service in England. It is based on the principle that close genetic relatives such as a parent and child or siblings wll have more DNA in common than unrelated persons.
When a search is made and a number of possible relatives have been identified, further profiling techniques are used to verify or exclude the possibility of relationship with the unidentified offender.
The use of Familial DNA Searching is controversial, particularly in the United States. Although openly carried out in California and Colorado, familial searching is banned in Maryland. Critics describe it as an invasion of privacy or a 'genetic fishing expedition'.
However, the technique proved effective in identifying a serial killer suspect in California known as the 'Grim Sleeper'.
This is how ABC reported the news of the Grim Sleeper suspect's arrest.
Finally, here is an excellent article detailing successful cases where familial DNA searching has been used, more about the technique itself and the arguments for and against the technique.
Familial Seaching: Extending the Investigative Potential of DNA Typing
Let's hope familial DNA searching proves its worth in the Debbie Linsley case.
Debbie, 26, worked in Edinburgh but had been attending a management course in London. Her parents lived only 15 miles or so from London, so it was a good chance to have a family get-together, particularly as Debbie was going to be a bridesmaid at her brother's wedding in two weeks time.
Gordon dropped off Debbie at the station and she caught the 14.16 Orpington to London Victoria train.
In those days, many of the train carriages had no corridors. Instead, they were divided into compartments. Within each compartment, the seats faced each other along its width and there was a slam door on either side.
If you were travelling on your own at a quiet time of the day, you ran the risk of being in dubious company at some point in your journey.
Some six minutes away from London Victoria station, Debbie's train stopped at Brixton to pick up passengers. In that final six minutes between Brixton and London Victoria, Debbie was stabbed eleven times in a frenzied attack. She put up strong resistance and managed to injure her attacker. However, she died from a stab wound to the heart.
Debbie's body wasn't discovered until ten minutes after the train arrived at London Victoria. Her attacker was long gone. At that time, there was no CCTV to record the passengers leaving the train.
The police investigation was thorough but the murderer has never been caught. The murder weapon has also never been recovered.
But the killer did leave a small sample of his blood at the scene. Although DNA profiling was not in use in 1988, the case has been subject to periodic reviews. As a result, the new investigations have taken full advantage of the latest techniques in DNA profiling. Finally, the scientists were able to generate a full DNA profile of the crime scene blood.
But the killer's DNA profile isn't on the National DNA Database.
Investigators are convinced that Debbie did not know her killer. They also discount the 'known killer' theory. This is because a person like Debbie's killer would surely have committed other crimes. If so, he would more than likely have been arrested for some of them and had a mouth swab taken for DNA profiling.
Maybe the killer is dead.
But 25 years after Debbie's murder, another cold case review is taking place. This time the investigators propose using Familial DNA Searching. Instead of searching the National DNA Database for a profile that matches the crime scene profile, scientists will search for relatives of the offender who may be on the Database.
One argument for its use is that criminality tends to run in families. Another argument is that it is a way of keeping the investigation going.
Familial DNA Searching was developed in 2002 by the Forensic Science Service in England. It is based on the principle that close genetic relatives such as a parent and child or siblings wll have more DNA in common than unrelated persons.
When a search is made and a number of possible relatives have been identified, further profiling techniques are used to verify or exclude the possibility of relationship with the unidentified offender.
The use of Familial DNA Searching is controversial, particularly in the United States. Although openly carried out in California and Colorado, familial searching is banned in Maryland. Critics describe it as an invasion of privacy or a 'genetic fishing expedition'.
However, the technique proved effective in identifying a serial killer suspect in California known as the 'Grim Sleeper'.
This is how ABC reported the news of the Grim Sleeper suspect's arrest.
Finally, here is an excellent article detailing successful cases where familial DNA searching has been used, more about the technique itself and the arguments for and against the technique.
Familial Seaching: Extending the Investigative Potential of DNA Typing
Let's hope familial DNA searching proves its worth in the Debbie Linsley case.
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