Unit 3

• CSI/ SOCO


  Crime scene investigators or scenes of crime officers (SOCOs), usually civilians rather than police officers, who undergo specialist training and often have a science degree. Their role is to collect and process evidence from crime scenes, post mortems and accidents, preserving evidence in an uncontaminated condition.
• CSI/ SOCO


  • Taking charge of the crime scene, liaising with police, photographing crime scenes, recovering physical/biological evidence, packaging and documenting evidence, attending post mortems, advising police, giving evidence in court
• Forensics


  Applying scientific knowledge to crime and the legal system. Forensic scientists analyse and interpret evidence recovered from crime scenes, producing reports for the court.
• Forensics


  • Specialising in areas like DNA analysis, fire analysis, toxicology, computing, psychology, forensic anthropology
• Police


  Usually the first on the scene, required to safeguard the public, attend to anyone injured, arrest suspects, secure the crime scene to conserve evidence.
• Police


  • Detectives manage complex investigations, work with specialist departments, can study policing at university. The 'golden hour' immediately after a crime requires quick action to conserve the scene and take statements.
• Pathologist


  Medical doctors who specialise in the causes of disease and death, conducting detailed examinations of bodies, organs and tissues in post mortems to advise the police and produce reports for the coroner and court.
• Pathologist


  • Providing a 24/7 service to assist police and coroner, establishing cause of death in suspected homicides. Only around 35 in the UK, so more wait time.
• CPS


  The Crown Prosecution Service, an independent prosecution agency set up in 1986, with over 2,000 qualified barristers and solicitors who decide whether to prosecute based on the evidence provided by police.
• CPS


  • Lawyers, paralegals, support staff. University degrees and postgraduate qualifications required, taking 5-6 years to become a barrister and 6+ years to become a solicitor.
• Techniques of Investigation


  1. Acquisition (witnessing and absorbing)

  2. Retention (storing info in memory)

  3. Retrieval (recalling the memory)
• Memory


  • Duration= longer experience= better memory
  • Time of day- full day or full night= better
  • Time distortion- over estimate the length of emotional or traumatic events
  • Violence distraction- recall a violent event less accurately as anxiety impairs memory
  • Weapon focus- when weapon is involved we don't notice the details
  • Time- the longer ago something happens, the less it can be remembered (golden hour)
  • Discussion- aids recall but reduces anxiety
  • Certain questioning can affect recall
• Loftus and Palmer


  Wording can give a interpretation about the event
• Memories can be led into a false EWT
• Intelligence


  Information from many sources that has been recorded and evaluated. It is stored in different databases that the police can access.
• Databases


  • The Police National Database
  • The Police National Computer
  • Crimint and the gangs matrix
  • International databases
• Police National Database


  • 3.5billion searchable records made up of 220 linked databases
• Police National Computer


  • Stores over 12 million people's arrests, convictions and police cautions linked to biometric databases for fingerprints and the National DNA database
  • Vehicle registration information on 48 million people with a licence and those disqualified
  • Information on missing people and wanted people
• The gangs matrix has been criticised as racially discriminatory and in 20 the Met police had to remove over 1000 young black men. In 2017 it had a leak and 203 addresses were accidentally linked and were found by rival gangs, some named suffered serious violence.
• Forensic evidence


  Biological materials, prints, items, paint etc from a crime scene
• It is essential that the scene is strictly controlled to avoid contamination
• DNA


  • Found in every cell in the body and each person's DNA is unique (except for identical twins)
  • Highly sensitive techniques have been developed for the extraction and rapid analysis of minute quantities of DNA samples
• DNA profiling


  The most important development in solving serious crime since fingerprinting was invented
• Preserving the evidence


  Most contamination occurs by handling items without gloves, breathing, sneezing or coughing on them
• DNA from relatives


  • Blood relatives have similar profiles to one another and can provide a Familiar match
  • Can be used to reduce the suspect pool and look with a person's family for a suspect
• DNA can also help to identify deceased victims of homicides, suicide and accidents
• Investigators in serious crimes

  • Wear protective clothing to protect themselves from hazardous substances as well as from them contaminating the evidence which could affect prosecution
  • Use a 'scene suit', overshoes and two pairs of gloves
• Concerns around the storage and keeping of DNA from those who had been found innocent or given an elimination sample
• Investigators in less serious crimes

  • Only use a mask and gloves
• The Equality and Human Rights Commission's ruling in December 2008 which stated that DNA could not be stored and saved for those found innocent of the crime that they were accused of
• Contamination of evidence


  The exchange principle - Locard's exchange principle was a pioneer of forensic science, and investigators always work from the principle "every contact leaves a trace"
• Protection of Freedoms Act 2012 - requires all DNA samples to be destroyed within 6 months of being taken. This allows sufficient time for the sample to be analysed and a DNA profile to be produced for use on the database
• DNA used to be very expensive to process and analyse. However the costs of DNA sample analyse is now around £20
• Outdoor crime scene


  • Most vulnerable to loss or contamination of evidence
  • Individuals with access can potentially alter, destroy or contaminate evidence
  • Greatest risk is when officers fail to secure the crime scene properly
  • Weather conditions can also destroy or ruin evidence
• Types of evidence


  • Physical
  • Testimonial
  • Hearsay
  • Forced confession
  • Entrapment
• Problems matching DNA


  • To obtain a match the suspect needs to be on the database already
  • Advances mean that it may soon be possible to identify the colour of perpetrators' hair, eyes and skin and approx age from the DNA sample
  • Contamination can lead to miscarriage of justice
• CCTV


  • Images from cameras on streets and businesses
  • Can be used to trace a person's movements
  • Each person in the UK is captured up to 30 times a day on CCTV
• Physical evidence


  'Real evidence' = actual physical material, such as DNA extracted from blood stains, weapons, and stolen goods. These are compared with control samples from suspects to see if there is a match
• Processing physical evidence


  1. Collection

  2. Transfer

  3. Storage

  4. Analysis
• CCTV as an investigative technique


  • Gives 24 hour coverage
  • Provides a visual record
  • Can be sent out via media
  • Can be used to identify suspects
  • Can incriminate someone or show their innocence