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Timings
● Day 1:
○ AC1.1 - 45 minutes
○ AC1.2 - 75 minutes (3 techniques)
● Day 2:
○ AC1.2 - 25 minutes (1 technique)
○ AC1.3 - 30 minutes
○ AC1.4 - 25 minutes
○ AC2.1 - 20 minutes
○ AC2.2 - 20 minutes
○ AC2.3 - 20 minutes
○ AC2.4 - 40 minutes
● Day 3:
○ AC2.4 - 5 minutes
○ AC2.5 - 30 minutes
○ AC3.1 - 70 minutes
○ AC3.2 - 15 minutes (1 subheading)
● Day 4:
○ AC3.2 - 55 minutes (3 subheadings)
Contents
AC 1.1 - Evaluate the effectiveness of the roles of personnel involved in criminal investigations 2
AC 1.2 - Assess the usefulness of investigative techniques in criminal investigations 6
AC 1.3 - Explain how evidence is processed 11
AC 1.4 - Examine the rights of individuals in criminal investigations 14
AC 2.1 - Explain the requirements of the CPS for the prosecution of suspects 15
AC 2.2 - Describe the trial processes 16
AC 2.3 - Understand rules in relation to the use of evidence in criminal cases 18
AC 2.4 - Assess key influences affecting the outcome of criminal cases 20
AC 2.5 - Discuss the use of laypeople in criminal cases 24
AC 3.1 - Examine information for validity 27
AC 3.2 - Draw conclusions from information 33
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AC 1.1 - Evaluate the effectiveness of the roles of personnel
involved in criminal investigations
Crime Scene Investigators
Crime Scene Investigators (CSIs), which work very closely with the police, are typically
responsible for completely securing the crime scene and subsequently gathering and
categorising evidence from either the area itself, as well as any other incidents or post-
mortems that link to the crime in question. CSIs collect this evidence in the form of images,
physical evidence like fingerprints, shoe prints, clothing and firearms, and biological
evidence such as blood, hair and semen.
It is important that the evidence is properly collected, labelled and kept in an uncontaminated
condition so that it can be used in a court of law to either prove a suspect guilty or innocent.
In addition, in the present day, criminal cases are becoming more complex and difficult to
investigate as perpetrators of various crimes increasingly have great knowledge and
experience when it comes to committing crimes while leaving little traces of evidence behind.
Fortunately, this emphasises the importance of the involvement of CSIs. They are highly
trained and qualified in this field of work meaning they are able to locate and make available
any form of evidence right down to a couple strands of hair. They also carry out many
procedures to minimise the risk of any contamination, including the use of protective
clothing, like gloves, a bodysuit and facemasks, and using a common approach path to enter
and exit the crime scene. As a result, the majority of the time, the evidence that is collected
benefits the court case and aids to solve it - this helps to provide justice. Moreover, their
services usually operate on a 24/7 on-call system so they are widely available to help many
different criminal investigations at any point in time.
However, as with almost any difficult job out there, CSIs are prone to malpractice - whether
that be intentional or not - which can result in evidence becoming contaminated and
therefore inadmissible in court, or completely missed out on and thus leading to possible
errors when decisions are being made within court. Additionally, the process they undertake
on a crime scene is relatively time-consuming and expensive which isn’t in favour of the
declining police budgets across some police forces. Consequently, the forces that cannot
afford a sufficient number of CSIs, as well as the professional equipment they require, may
struggle to properly collect all evidence in an uncontaminated condition and therefore fail to
effectively carry out their criminal investigation. In the case of the murder of Meredith
Kercher in a shared flat in 2007, the malpractice of the CSIs, in particular, failing to wear
protective clothing on the crime scene and incorrectly interpreting vital forensic evidence, led
to the contamination of important evidence and therefore the wrongful conviction of Amanda
Knox and her boyfriend.
CSIs are vital for one of the first major steps in a criminal investigation which is the collection
of evidence on the crime scene, which allows for the investigation to progress onwards.
However, if any minor errors occur during their work, investigations may not be able to go
ahead or innocent people may be wrongfully convicted.
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Police officers
Police officers are responsible for arriving first and securing the crime scene so that all
evidence is preserved in an uncontaminated condition ready for the criminal investigation to
begin, such as the arrival of the CSIs. They also help the public, attend to any injured
people, take statements from any witnesses and victims, and make arrests on any suspects.
A police officers’ role is very important for a criminal investigation because it ensures that the
evidence, which can later be processed and used in a court of law, is preserved and the
public order at the scene is maintained. Furthermore, in the case of more complex crimes,
specialist divisions within police forces, such as detectives, are highly qualified and can
therefore aid in solving more challenging investigations. Due to the fact that there is 43
police forces across England and Wales and that they each operate on a 24-hour service,
regardless of the location of the crime, a police unit will always be dispatched as quickly as
possible which increases the likelihood of keeping the crime scene secure, evidence
uncontaminated and allowing the investigation to begin. Moreover, the role of the police is
extremely effective as they work closely with the CPS in order to successfully solve and
prosecute criminal investigations; the CPS largely relies on the work of police forces who
investigate and propose the cases, therefore if they weren’t present, no court cases would
go ahead.
Although, from 2010 up until 2018, the number of police officers in England and Wales
decreased each year, with the current amount being 7% fewer than in 2010. Not to mention,
over the past decade, direct government police funding has fallen by 30% which is limiting
police resources. Both of these declining figures are resulting in low availability of police
officers and therefore many criminal investigations are going unheard of or unsolved. Due to
the severe shortages in specialist officers like detectives, several complex investigations are
being led by officers who lack the appropriate expertise resulting in vital evidence becoming
contaminated, increasing the likelihood of wrongful convictions, and investigations making
insufficient progress. Additionally, despite the extensive training required to become a police
officer, personal prejudices and discriminatory attitudes are overtaking their expertise
leading to increased bias against certain groups of people. All of these factors significantly
reduce the effectiveness of police officers in criminal investigations. In particular, this poor
expertise, misconduct and even institutional racism can be seen in the case of the murder of
Stephen Lawrence - an 18 year old black British teenager - in 1993. It was found that police
officers failed to give sufficient first aid on the scene and didn’t make any arrests for more
than two weeks despite them repeatedly being given the names of suspects/leads with lots
of evidence behind it.
Forensic scientists
Forensic scientists are responsible for analysing and interpreting evidence, including bodily
fluids, hair, clothing fibres, paint, glass and drugs, that has been recovered from a crime
scene in a laboratory through many different techniques, such as blood pattern analysis,
DNA profiling, mass spectrometry, hair and fibre analysis and chromatography. The
information they discover can then be used in court to help in the decision making and the
subsequent conclusive verdict that is produced from the criminal investigation.
Forensic scientists are highly qualified therefore, after they review and interpret the
evidence, the information they gain can be used to prove a suspect guilty or innocent; due to
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their great expertise, their analysis of the evidence is usually highly accurate, preventing any
injustices. In addition, in the present day, criminal cases are becoming more complex and
difficult to investigate, therefore the role of forensic scientists is vital when the perpetrators
have great knowledge and experience when it comes to committing crimes with little traces
of evidence being left behind.
On the other hand, the distinctive knowledge and skills that they have developed to get into
this occupation and the difficulty behind their work, means that their services are expensive
and time-consuming. This reduces their effectiveness because the people in charge of many
complex criminal investigations cannot always afford sufficient forensic scientists to analyse
all of the evidence on a crime scene, which can result in conclusions not being made.
Similarly to the crime scene investigators, these scientists may either deliberately or
accidentally incorrectly handle/analyse the evidence and therefore the information they
provide to the court can mislead them to come to the wrong verdict. Also, due to the
challenging nature of their work, these experts may disagree with other forensic scientists on
the opposing side of the court and, as the court doesn’t have the same specialties, they may
struggle to assess who is right, elongating the criminal investigation. Malpractice by forensic
scientists can be seen in the case of Adam Scott whose DNA wasn’t removed and disposed
of from a plastic tray in a laboratory, and therefore was unintentionally re-used in a rape
case later down the line. The incorrect handling of this DNA evidence led to Adam being left
in custody for 5 months even though he was completely innocent.
Forensic pathologists
Forensic pathologists are doctors that are responsible for performing autopsies to find the
cause, such as an underlying health condition or gunshot wound, and manner, like homicide,
suicidal, accidental or natural, of death. The information that pathologists discover is very
important because it can reveal key evidence about how and when someone has died,
which can assist with criminal investigations when it comes to proving a suspect guilty.
Forensic pathologists are highly effective as they are highly specialised with lots of expertise
in areas such as anthropology, pathology and anatomy. To become a pathologist, it requires
7 further years of training after becoming a doctor. Due to their specialist expertise and the
complex nature of pathology, they tend to be highly accurate in their decision making,
limiting miscarriages of justice. Additionally, it is important that forensic pathologists are part
of an investigation for many aspects, not just only the examination of the deceased; they
educate other personnel on the crime scene, like CSIs and police, on how to retrieve the
body/bodies to preserve the evidence and they assist in court by providing specialised
expert witness testimonies to help juries come to the correct verdict.
However, there are only 35 Home Office-registered forensic pathologists in England and
Wales meaning the availability of them is extremely low. As a result, criminal investigations
that require an autopsy to be carried out can be delayed for long periods of time; this
reduces their effectiveness as each pathologist will have a large workload and therefore be
more prone to errors due to rushing or stress. Like forensic scientists, their knowledge, skills
and abilities mean their services are well-paid and therefore can be very expensive for those
leading investigations to pay for. In addition to this, any mistakes during their work can result
in them coming to incorrect decisions, and differences in interpretation between multiple
pathologists can cause conflicts and, as members of the court generally don’t have the same
