Forensic Investigations Involving DNA Data
Section 1
The history of the DNA database
The UK national DNA database holds the DNA profiles and the relevant DNA samples from a number of UK individuals
and is the largest database of its kind and is continuing to grow. Before the creation the DNA database, in 1984, police
were allowed to ask doctors for a blood sample to use for DNA testing and to assist in the investigation of a serious
crime, with the consent of volunteers but the DNA technology was still very limited in its use around this time. Then in
1993, it was recommended that a DNA database should be created but there was concern around public confidence in
the criminal justice system as there were number of cases where there had been miscarriages of justice, like the
Birmingham 6 who had been framed for placing an IRA bomb, but this had then resolved, and the database was
proposed as a form of forensic identification with the potential to eliminate suspects. The database was then created
in 1995 using the Second-Generation Multiplex DNA profiling system and only held the data of convicted criminals or
those awaiting trial, the samples were then destroyed once they were proven innocent.
DNA data is used to help convict people who have been accused of a crime. However, over the years, the legislation
that concerned samples being taken and stored had changed and as a result of this, the database expanded rapidly to
include samples of the innocent and children as well as the guilt. By 2008, the police in Wales, Northern Ireland and
England were able to collect a sample without the need for consent once the person was arrested but not for minor
offences and the samples were kept permanently instead of temporarily. There are currently 6.6 million DNA profiles
currently on the database.
How does the DNA database help in forensic investigations?
The DNA database helps with forensic investigations through the use of short tandem repeats (STR) analysis. Within our
DNA, there are short tracts of repetitive DNA that can become common in most humans, which can be useful for such
things like investigating crime scenes as well as paternity tests. STR analysis looks at these short tandem repeats and
uses them to compare the specific loci between two pieces of DNA and the loci changes from country to country. In the
UK, the DNA-17 loci are in use and analyse 16 repeats and a gender identifier, making the power to match or eliminate
a suspect much easier. In Scotland, they use a multiplex 24 locus system, in the rest of Europe 20 loci are used and in
America, they use the CODIS 13 core loci system.
A case in which DNA has been helpful in forensic investigations was the case of Colin Pitchfork. He was the first person
to be convicted of murder using fingerprinting evidence. He raped and murdered two girls in Leicestershire in 1983 and
1986 and because Buckland was the first suspect, he had learning difficulties and admitted to his crimes, but his DNA
didn’t match the semen sample found in the victims. A mass DNA screening was carried out from all the males who
lived within the proximity of the two crimes but there was still no match, and it wasn’t until a police officer heard about
a man who was bragging about being paid £200 by a friend where Colin was identified.
Evaluate the use of DNA data
The use of DNA data can be extremely useful when trying to solve a case but there are instances where it will go wrong
which can question the validity of DNA data when trying to solve a crime. One reason for this is that the new
technology that can collect microscopic evidence creates more problems and it is unclear if trace DNA is skin cells,
saliva or any other bodily fluids. Following this, sometimes material can build up from multiple people and this can be
hard to decipher apart and that some people will leave larger DNA samples than others which can lead to some people
being wrongly accused of a crime that they didn’t do. An example in which this happened is the case of David Butler. He
was a retired taxi driver who was arrested for the murder of Anne Marie Foy, a sex worker who was strangled in 2005.
A partial fingerprint was found on Foy’s cardigan and her fingernails where there was a mixture of Foy’s DNA and
Butler’s DNA and because Butler’s DNA was in the database in 1993 after a break-in at his house address, making them
elimination prints, he was convicted and was later released as his defence lawyer argued that Foy could’ve touch the
coins after Butler had handled them.
Section 1
The history of the DNA database
The UK national DNA database holds the DNA profiles and the relevant DNA samples from a number of UK individuals
and is the largest database of its kind and is continuing to grow. Before the creation the DNA database, in 1984, police
were allowed to ask doctors for a blood sample to use for DNA testing and to assist in the investigation of a serious
crime, with the consent of volunteers but the DNA technology was still very limited in its use around this time. Then in
1993, it was recommended that a DNA database should be created but there was concern around public confidence in
the criminal justice system as there were number of cases where there had been miscarriages of justice, like the
Birmingham 6 who had been framed for placing an IRA bomb, but this had then resolved, and the database was
proposed as a form of forensic identification with the potential to eliminate suspects. The database was then created
in 1995 using the Second-Generation Multiplex DNA profiling system and only held the data of convicted criminals or
those awaiting trial, the samples were then destroyed once they were proven innocent.
DNA data is used to help convict people who have been accused of a crime. However, over the years, the legislation
that concerned samples being taken and stored had changed and as a result of this, the database expanded rapidly to
include samples of the innocent and children as well as the guilt. By 2008, the police in Wales, Northern Ireland and
England were able to collect a sample without the need for consent once the person was arrested but not for minor
offences and the samples were kept permanently instead of temporarily. There are currently 6.6 million DNA profiles
currently on the database.
How does the DNA database help in forensic investigations?
The DNA database helps with forensic investigations through the use of short tandem repeats (STR) analysis. Within our
DNA, there are short tracts of repetitive DNA that can become common in most humans, which can be useful for such
things like investigating crime scenes as well as paternity tests. STR analysis looks at these short tandem repeats and
uses them to compare the specific loci between two pieces of DNA and the loci changes from country to country. In the
UK, the DNA-17 loci are in use and analyse 16 repeats and a gender identifier, making the power to match or eliminate
a suspect much easier. In Scotland, they use a multiplex 24 locus system, in the rest of Europe 20 loci are used and in
America, they use the CODIS 13 core loci system.
A case in which DNA has been helpful in forensic investigations was the case of Colin Pitchfork. He was the first person
to be convicted of murder using fingerprinting evidence. He raped and murdered two girls in Leicestershire in 1983 and
1986 and because Buckland was the first suspect, he had learning difficulties and admitted to his crimes, but his DNA
didn’t match the semen sample found in the victims. A mass DNA screening was carried out from all the males who
lived within the proximity of the two crimes but there was still no match, and it wasn’t until a police officer heard about
a man who was bragging about being paid £200 by a friend where Colin was identified.
Evaluate the use of DNA data
The use of DNA data can be extremely useful when trying to solve a case but there are instances where it will go wrong
which can question the validity of DNA data when trying to solve a crime. One reason for this is that the new
technology that can collect microscopic evidence creates more problems and it is unclear if trace DNA is skin cells,
saliva or any other bodily fluids. Following this, sometimes material can build up from multiple people and this can be
hard to decipher apart and that some people will leave larger DNA samples than others which can lead to some people
being wrongly accused of a crime that they didn’t do. An example in which this happened is the case of David Butler. He
was a retired taxi driver who was arrested for the murder of Anne Marie Foy, a sex worker who was strangled in 2005.
A partial fingerprint was found on Foy’s cardigan and her fingernails where there was a mixture of Foy’s DNA and
Butler’s DNA and because Butler’s DNA was in the database in 1993 after a break-in at his house address, making them
elimination prints, he was convicted and was later released as his defence lawyer argued that Foy could’ve touch the
coins after Butler had handled them.
