AC 1.1: Explain the Effectiveness of the Roles of Personnel Involved in Criminal Investigations
Several personnel are involved in criminal investigations, including police officers, SOCOs (Scene of
Crime Officers), the CPS, pathologists and forensic psychologists.
Police officers are the first personnel to arrive on the scene and use the ‘golden hour’ to collect vital
evidence. They have a key role of securing the crime scene during this ‘golden hour’ and
safeguarding the public but will call other services if needed. Due to this nature of the police, they
have many strengths, such as all officers receiving specialist training. As a result, they are very
efficient at dealing with all crimes they may come across. Furthermore, due to the 24-hour
availability of the police, it is ensured they will respond to crime scenes as quickly as possible, which
therefore makes the possibility of keeping it secure much higher.
However, the police do suffer from downfalls, with a key limitation being that of police brutality and
not protecting crime scenes or mishandling evidence. They have also often been accused of
discrimination, in particular institutional racism. A well-known example of this is the case of Stephen
Lawrence and the McPherson report, which found that the investigation into his killing was “marred
by a combination of professional incompetence, institutional racism and a failure of leadership.” The
report gave 70 recommendations to show “zero tolerance” for racism in society. 67 of these
recommendations led to changes in practice within two years of the report’s publication.
Another limitation of the police is some of the unethical methods and tactics that they have been
known to use, such as the ‘honeytrap’ technique. This technique was used in the case of Colin Stagg
when the police used a honeytrap to try to get him to confess to the murder of Rachel Nickell. By use
of this method, an undercover police officer known as ‘Lizzie’ pretended to show a romantic interest
in him to elicit a confession. He never confessed, however the judge still ruled that “excessive zeal”
had been used to incriminate him and called police efforts “deceptive conduct of the grossest kind.”
Scene of Crime Officers (SOCOs), also known as Crime Scene Investigators (CSI), play a significant
role in criminal investigations. They are not police officers but are on call 24/7. They may be
employed by police forces or may work for private companies, but their role of collecting and
processing evidence from crime scenes stays the same. They achieve this by photographing,
recovering, and packaging physical evidence, followed by giving testimonial evidence in court. As a
result of their expertise, SOCOs are trained in using a wide range of equipment to collect evidence,
which can benefit the investigation greatly. Also, since they are available at all hours of the day, they
can reach crime scenes as soon as possible and do not need to wait until morning, by which point
evidence could have been contaminated.
The role of a SOCO also has a few limitations, including the crime scenes often having emotional or
traumatic images which could affect SOCOs in the long-term. A second limitation is there being a risk
of contaminating yourself with toxic or dangerous substances, and there also being a risk of
contamination at the crime scene despite any steps that might be taken to minimise these risks. An
example of a case affected by the contamination of evidence is that of Amanda Knox, who was
arrested for the murder of Meredith Kercher very soon after her body was discovered, and before all
the physical evidence from the crime scene had been collected. Even when the culprit’s DNA was
found, the police still pursued Knox due to finding both her and Kercher’s DNA on the suspected
murder weapon. However, Kercher’s DNA was later said to be present due to contamination. During
the investigation, proper DNA procedures were not followed – for example, Kercher’s tampered-
with bra clasp was collected so long after her death that contamination was highly likely.
The CPS also plays a role in criminal investigations and is an independent body across 14 regional
offices also offering a 24/7 direct service. Over 2000 barristers work on 500,000 cases a year, and the
CPS advises police on the charging and prosecution of cases they are working on, often rejecting
