AC1.2
There is a wide range of investigative techniques used in different criminal investigations.
These include forensics, surveillance, interview techniques and offender profiling.
One technique used in criminal investigations is forensics. Forensics is the use of scientific
methods in order to analyse evidence that has been collected from the crime scene. There is
a rather broad field of practices involved in forensics, including fingerprint & DNA analysis,
firearms, toxicology, microscopy and fire debris. Forensics has developed greatly in the past
100 years and in today's society police are always accompanied by a range of forensic
experts. Forensic science is useful for a long list of reasons, the first reason being that
everybody’s DNA is unique. This is useful because it means that the exact people involved
in a crime can be identified, allowing for very high reliability. DNA can also be collected
through blood samples found on the crime scene, exemplified in the case of Colin Pitchfork.
Pitchfork was found guilty of the 1983 & 1986 murder of both Lynda Mann (1983) and Dawn
Ashworth (1986) where at the time of the second murder, Alec Jefferys, a british geneticist
had collected blood samples from all men living in the area and had found the DNA of
Pitchfork on the murder victims- this happened to be the first criminal conviction using DNA
evidence. On the contrary, this doesn't mean that forensics are always useful for this reason
as identical twins share the same DNA which could raise some difficulty in finding the
perpetrator. Another reason forensics is useful is because DNA from closely related relatives
have lots of similarities. This is useful because if the DNA of the exact perpetrator is not
stored on the national database but a close family member is, it can lead to matching the
exact offender based on their relatives DNA. A case example of this is the case of Collette
Aram, who was murdered in 1983 before DNA was established as an investigative technique
but as forensics developed, after 26 years, police went back to the case and were able to
establish Paul Hutchinson as the murder due to the use of a close relatives DNA sample
even though Hutchinson’s was not on the National DNA Database. A third important
strength is that it can be used to help substantiate innocents as well as guilt. For example,
the use of DNA has helped overturn over 250 jury convicted individuals in the USA alone.
However despite this, forensics can produce many limitations in a criminal investigation. It's
possible that trace amounts of DNA can end up falsely implicating a person, seen in the
case of David Butler. David Butler was charged with the murder of a prostitute, Anne Marie
Foy, as a result of a partial DNA match. His DNA was found under her fingernails. However,
8 months later Butler was acquitted of the murder as it was shown that he suffers a dry skin
condition, explaining his skin being found on the victim. Forensics can be useful for a wide
variety of types of crime. It is used mainly in violent crimes such as murders, assaults,
sexual abuse and firearms however it can also be extremely useful with property crimes e.g.
burgalary or robbery as fingerprints can be found on doorhandles etc. However, a type of
crime that forensics most likely won't be useful for is electronic crimes as no DNA can be
found with crimes that occur on the internet. Forensics is also extremely useful for multiple
different situations, such as at the crime scene (for collection and discovery), in the
laboratory (for analysis) and at the police station (to look at the national database and find
the suspect).
The second technique used in criminal investigations is surveillance, which includes
monitoring, observing or listening to people, their movements, conversations or other
There is a wide range of investigative techniques used in different criminal investigations.
These include forensics, surveillance, interview techniques and offender profiling.
One technique used in criminal investigations is forensics. Forensics is the use of scientific
methods in order to analyse evidence that has been collected from the crime scene. There is
a rather broad field of practices involved in forensics, including fingerprint & DNA analysis,
firearms, toxicology, microscopy and fire debris. Forensics has developed greatly in the past
100 years and in today's society police are always accompanied by a range of forensic
experts. Forensic science is useful for a long list of reasons, the first reason being that
everybody’s DNA is unique. This is useful because it means that the exact people involved
in a crime can be identified, allowing for very high reliability. DNA can also be collected
through blood samples found on the crime scene, exemplified in the case of Colin Pitchfork.
Pitchfork was found guilty of the 1983 & 1986 murder of both Lynda Mann (1983) and Dawn
Ashworth (1986) where at the time of the second murder, Alec Jefferys, a british geneticist
had collected blood samples from all men living in the area and had found the DNA of
Pitchfork on the murder victims- this happened to be the first criminal conviction using DNA
evidence. On the contrary, this doesn't mean that forensics are always useful for this reason
as identical twins share the same DNA which could raise some difficulty in finding the
perpetrator. Another reason forensics is useful is because DNA from closely related relatives
have lots of similarities. This is useful because if the DNA of the exact perpetrator is not
stored on the national database but a close family member is, it can lead to matching the
exact offender based on their relatives DNA. A case example of this is the case of Collette
Aram, who was murdered in 1983 before DNA was established as an investigative technique
but as forensics developed, after 26 years, police went back to the case and were able to
establish Paul Hutchinson as the murder due to the use of a close relatives DNA sample
even though Hutchinson’s was not on the National DNA Database. A third important
strength is that it can be used to help substantiate innocents as well as guilt. For example,
the use of DNA has helped overturn over 250 jury convicted individuals in the USA alone.
However despite this, forensics can produce many limitations in a criminal investigation. It's
possible that trace amounts of DNA can end up falsely implicating a person, seen in the
case of David Butler. David Butler was charged with the murder of a prostitute, Anne Marie
Foy, as a result of a partial DNA match. His DNA was found under her fingernails. However,
8 months later Butler was acquitted of the murder as it was shown that he suffers a dry skin
condition, explaining his skin being found on the victim. Forensics can be useful for a wide
variety of types of crime. It is used mainly in violent crimes such as murders, assaults,
sexual abuse and firearms however it can also be extremely useful with property crimes e.g.
burgalary or robbery as fingerprints can be found on doorhandles etc. However, a type of
crime that forensics most likely won't be useful for is electronic crimes as no DNA can be
found with crimes that occur on the internet. Forensics is also extremely useful for multiple
different situations, such as at the crime scene (for collection and discovery), in the
laboratory (for analysis) and at the police station (to look at the national database and find
the suspect).
The second technique used in criminal investigations is surveillance, which includes
monitoring, observing or listening to people, their movements, conversations or other
