AC 1.2 assess the usefulness of investigative techniques in criminal investigations
Forensics
Forensics are scientific techniques used by experts to discover different evidence that can
be used to show when the crime was committed as well as the cause and the individuals
involved. There are 7 most common types of forensic evidence, these include:
entomology ,dentistry, fingerprints, ballistics and DNA. Forensic experts analyse all this
evidence that is recovered from a particular crime scene, which can end up solving different
cases.
Ballistics
Ballistics is one form of forensics used in solving cases. Ballistics is the study of bullets or
ballistic missiles where an object such as a bullet is propelled from a burst of energy, the
gun. Ballistics can determine the distance, angle and even the time when a gun was fired by
carefully analysing the damage the bullet suffers upon hitting a rigid surface. Also Bullet
casing left behind at a crime scene can be analysed by ballistic specialists and matched to a
certain gun through firearms databases. Ballistics can be useful in investigating crimes
where a gun is involved. For example, using the case of Jessica Lal, she was shot dead at a
bar in New Delhi. Forensic ballistics helped solve the case, various firearm evidence
including two empty cartridge cases of a .22 caliber were recovered from the crime scene
and belonged to Man Sharma. However, ballistics is not so useful in investigating crimes
such as tax fraud, because firearms are not used in these sorts of crimes.
DNA
DNA is a genetic footprint that is unique to each person. Almost every tissue or bodily fluid
contains DNA. Therefore, if hair, blood and dead skin is found at a certain crime scene, this
evidence can be used to identify a suspect. When the DNA is gathered and identified, the
national DNA database can make matches between a crime scene profile and a profile on
the database. DNA evidence can be useful in investigating violent or sexual offences as
blood,semen and hair is often left at the crime scene, this allows for a DNA profile to be
constructed. For example using the case of Colin Pitchfork, he was a double murderer, the
first murder was in 1983 and the second was in 1986. During this time Alec Jefferys was
pioneering profiling techniques by using DNA he was able to use his work to confirm that the
two murders were by the same person. The Leicestershire Constabulary and the Forensic
science teamed up to conduct a project in which 5,000 local men were asked to give a blood
or saliva sample. Pitchfork had persuaded his friend to impersonate him and provide the
sample. This was eventually discovered by the police who arrested Pitchfork to use Jefferys
DNA profiling technique to confirm he was the double killer. However, DNA evidence can
also be seen as not useful due to the fact DNA profiling is not 100% accurate, which
ultimately leads to a miscarriage of justice. For example using the case of David Butler, he
was charged with the murder of Anne Marie, as a result of a partial DNA match. Butler's
Lawyers were able to show the jury that the procedures used to obtain DNA were unreliable.
Also Butler suffered from a dry skin condition which meant he shed large flakes of skin,
therefore his DNA was easily transferred. Butler worked as a taxi driver and took the
passenger to the red light district, where the victim worked and DNA was passed on when
David gave change to the victim. This meant Butler was wrongly convicted of the murder
because the DNA profilling was inaccurate.
Forensics
Forensics are scientific techniques used by experts to discover different evidence that can
be used to show when the crime was committed as well as the cause and the individuals
involved. There are 7 most common types of forensic evidence, these include:
entomology ,dentistry, fingerprints, ballistics and DNA. Forensic experts analyse all this
evidence that is recovered from a particular crime scene, which can end up solving different
cases.
Ballistics
Ballistics is one form of forensics used in solving cases. Ballistics is the study of bullets or
ballistic missiles where an object such as a bullet is propelled from a burst of energy, the
gun. Ballistics can determine the distance, angle and even the time when a gun was fired by
carefully analysing the damage the bullet suffers upon hitting a rigid surface. Also Bullet
casing left behind at a crime scene can be analysed by ballistic specialists and matched to a
certain gun through firearms databases. Ballistics can be useful in investigating crimes
where a gun is involved. For example, using the case of Jessica Lal, she was shot dead at a
bar in New Delhi. Forensic ballistics helped solve the case, various firearm evidence
including two empty cartridge cases of a .22 caliber were recovered from the crime scene
and belonged to Man Sharma. However, ballistics is not so useful in investigating crimes
such as tax fraud, because firearms are not used in these sorts of crimes.
DNA
DNA is a genetic footprint that is unique to each person. Almost every tissue or bodily fluid
contains DNA. Therefore, if hair, blood and dead skin is found at a certain crime scene, this
evidence can be used to identify a suspect. When the DNA is gathered and identified, the
national DNA database can make matches between a crime scene profile and a profile on
the database. DNA evidence can be useful in investigating violent or sexual offences as
blood,semen and hair is often left at the crime scene, this allows for a DNA profile to be
constructed. For example using the case of Colin Pitchfork, he was a double murderer, the
first murder was in 1983 and the second was in 1986. During this time Alec Jefferys was
pioneering profiling techniques by using DNA he was able to use his work to confirm that the
two murders were by the same person. The Leicestershire Constabulary and the Forensic
science teamed up to conduct a project in which 5,000 local men were asked to give a blood
or saliva sample. Pitchfork had persuaded his friend to impersonate him and provide the
sample. This was eventually discovered by the police who arrested Pitchfork to use Jefferys
DNA profiling technique to confirm he was the double killer. However, DNA evidence can
also be seen as not useful due to the fact DNA profiling is not 100% accurate, which
ultimately leads to a miscarriage of justice. For example using the case of David Butler, he
was charged with the murder of Anne Marie, as a result of a partial DNA match. Butler's
Lawyers were able to show the jury that the procedures used to obtain DNA were unreliable.
Also Butler suffered from a dry skin condition which meant he shed large flakes of skin,
therefore his DNA was easily transferred. Butler worked as a taxi driver and took the
passenger to the red light district, where the victim worked and DNA was passed on when
David gave change to the victim. This meant Butler was wrongly convicted of the murder
because the DNA profilling was inaccurate.
