AC1.2
Forensic techniques are where science and analysis are applied to cases. This includes looking at
fingerprints, hair and fibres, computer forensics and footwear analysis. These techniques are
gathered at crime scenes, laboratories, and police station and are used for all types of crime
including violent crime, e-crime, and property crime. Some types of forensic techniques are:
Fingerprints: No one has the same fingerprints as anyone else making them important for
identification. Even identical twins have different fingerprints. Because of their uniqueness many
people will wear gloves whilst committing a crime, or wipe surfaces after, in order to remain
undetected.
Hair and fibres: DNA can be extracted from hair and fibres. Fibres can also be used to identify clothes
worn by the person who committed the crime allowing specific items to be identified. Hair and fibres
are usually collected at the crime scene or during an autopsy.
Computer forensics: These allow evidence to be stored and analysed. They can also be used to
recover data that has been lost or deleted. Devices that a suspect owns can be analysed to find out
about the suspect. These findings can be used as evidence.
Footwear analysis: This can be used to tie a suspect to a crime scene through tread marks or
evidence stuck in the tread of shoes. The soles of shoes can also provide information as it shows a
person’s unique style of walking. Marks on victims’ bodies may correspond to certain shoes. Through
analysis the height of suspects can also be estimated from their foot size.
Useful:
Forensic techniques are good as they can help to identify individuals. As all fingerprints are unique,
they are very useful for identification and a very reliable source of information. Information on
fingerprints and DNA is stored on a database meaning it can help solve future and past crimes. DNA
can help to solve crimes a long time in the past as it remains testable for a long time. In the case of
Sally Bowman, an 18-year-old model who was murdered and raped in 2005, her killer and rapist
were only found after his DNA was logged for a different crime. DNA can also be useful in linking
multiple crimes together. Because families share some DNA, links can be obtained through getting
the DNA form family members of the criminal. Collette Aram was a 16-year-old girl who got raped
and murdered in 1983 whilst on the way to her boyfriend’s house. Her killer and rapist only got
caught after his son was arrested by police for a different crime and his DNA was taken. This came up
as a partial match to DNA gathered of Collette’s killer. Computer forensics can help recover lost data
meaning that if a suspect deletes things form their devices that they believe to be incriminating, it
can often be recovered and used as evidence. This data can be very useful in finding out motive and
suspects. Shoeprints can be used to identify shoes worn and to estimate the height of a suspect
making them useful for creating a profile of the suspect. Also, each individual will have particular
treads on each of their shoes making more accurate individual identification. If the footwear can be
found the suspect may well be found too. Hair and fibres can be good for extracting DNA or
identifying clothing, both of which may be crucial for linking a suspect to a crime scene. In 2016,
clothing fibres and DNA were both crucial in linking Russel Bishop to the Babes in the Woods
murders which took place in 1986. This meant a conviction could finally be made, over 30 years after
the crime had occurred.
Not useful:
One disadvantage of forensic techniques is that if a perpetrators DNA or fingerprints aren’t already
on the database, they can’t be identified. Also, sometimes DNA only provides a partial match to
, someone making it harder to determine whether a certain person was responsible or not. This
means that this technique is only useful when paired with the necessary information. Forensic
evidence can also cause other evidence to be ignored in court due to people’s reliance on and trust
in forensics. This is dangerous as a DNA match doesn’t necessarily show guilt and perpetrators can
plant evidence. David Butler spent months in prison due to a partial DNA match linking him to a
murder. He was innocent but wasn’t released even when other evidence against him was disproved.
Fingerprint matches are subjective because they are compared by the human eye meaning miniscule
differences may not be noticed and different people may have different opinions. Forensic
techniques are expensive and time-consuming due to the extensive testing and there may be a lack
of forensic evidence available especially If a crime took place outdoors or in a highly populated area.
Also, if perpetrators wear gloves there will be no fingerprints to analyse. DNA present also doesn’t
necessarily show guilt. Lukis Anderson was thought to be guilty of the murder of Raveesh Kumra
after his DNA was found at the crime scene. However, it was later discovered that this DNA was
transferred by medics who went to the scene of the crime. These medics been treating Lukis in
hospital earlier that day. One issue with computer forensics is that a perpetrator will likely delete or
edit data they have that incriminates them. This may not always be able to be recovered. A
limitation of shoeprints is that they are not unique to an individual, only to a type of shoe. Although
treads are unique to a certain person’s shoes, these change quickly and after 3 months, tread marks
can no longer be accurately compared to shoes that have been worn since as the tread may have
changed significantly in this time.
Interviews are formal conversations used to gather information about what happened at the time of
a crime. This includes eyewitness interviews, expert interviews, victim interviews, and suspect
interviews. This type of evidence is collected at a police station, crime scene, or in the ‘street’. Initial
statements are usually taken at the crime scene when memories are fresh and urgent interviews are
often done in the ‘street’. However, most interviews occur in a police station. Interviews are also
used for all types of crime including e-crime, property crime, and violent crimes.
Eyewitness interviews: These are interviews done with the main witness of a crime. Eyewitnesses
give an account of what they saw happening. This can be used as crucial evidence in court as they
may be able to give the only unbiased, detailed description of a crime.
Expert interviews: These are interviews conducted with people who have expertise in a specific field.
This means they can give their opinion on elements of a crime that other may overlook, providing
insight into how or why it happened.
Victim interviews: These are interviews done with the victim(s) of a crime. Victims may also be the
key witness. These interviews are done in a way to try and make the victim feel unjudged, to try and
get them to open up and be honest about what happened.
Suspect interviews: These are interviews done with someone who has been suspected of a crime. In
these interviews the suspect won’t be comforted, instead the interviewer will try to trip them up to
get a confession.
Useful:
By avoiding too much questioning of victims, they may be more likely to open up and give crucial
information as they don’t feel they are being treated as a suspect. Important interview techniques
can be used to improve the reliability of witness statements. Interviews conducted at a crime scene,
soon after the crime occurred, can provide information on what happened that may later be
forgotten or distorted by talking to others. Interview methods can be used to get suspects to confess
and are hugely important when proving guilt. In the urgent interview of Wayne Couzens, the
