Week 5: Making and recognising faces
Our two detectives were careful to get a description of the perpetrators in the initial statements they took from the witnesses. But what can the police do with this description?
Finding a potential suspect and then determining whether that suspect is the perpetrator by seeing whether they are identified by an eyewitness are incredibly important components of a police investigation.
The clothing worn by the perpetrator and general characteristics such as their sex, age, height and build can be very useful when searching for them immediately after the crime has been committed. However, it would obviously be immensely problematic to prosecute someone simply because they had the same jacket, or were the same age and height as the person who committed a crime! Instead, police investigations and criminal prosecutions rely on eyewitnesses recognising and describing the face of the perpetrator, which makes the face recognition abilities of the witness very important indeed.
This week we will be exploring the psychology of face recognition and description, and looking at why eyewitness misidentification is such a prevalent cause of wrongful convictions.
First, we will consider the assistance that a witness may give to the police by describing the identity of a perpetrator. The procedures that the police employ to elicit this help are system variables, and hence controllable. In some cases, where the available evidence does not suggest a suspect, the witness may be asked to search through mug-shot albums containing photographs of known offenders. Alternatively, a composite image of the perpetrator may be constructed with the help of the witness and this is then publicised in the media in the hope that someone familiar with the perpetrator will see the composite image and identify them.