As the discipline of Investigative Psychology evolved, there was a recognition that psychologists could help police with a variety of things. As many of you will know, the majority of police work begins with collecting information. This can sometimes be challenging for officers as they need to decide on what information or evidence to collect. Of course, there is the basic forensic evidence to be collected from a crime scene, however, additional information at a crime can also be revealing. For example, how a victim and a perpetrator interact can tell us a lot about the offender.
There are several areas in policing that can benefit from applying aspects of Investigative Psychology. These can be how information is gathered from suspects, witnesses, or victims. It could be identifying where the offender is likely to live. It may even be drawing inferences about what characteristics the offender is likely to have.
But as any officer will tell you, the majority of work begins with interviewing. This is certainly one area that principles within psychology can have an impact on policing work. They need to interview the victim, any witnesses, and any suspects. However, as we have also previously discussed, this information may not always be accurate or truthful.
Eyewitness testimony is one area that has been greatly improved by understanding how memory and brain work. It is well understood that the information given by witnesses may not always be 100% correct. Eyewitnesses may give false or inaccurate information – this is not always intentional though. There can be many cases of innocent errors being made such as not identifying the suspect in an identity parade, not recalling the events they witnessed correctly and so on. One particular study within psychology set up an experiment in which a person entered a shop and performed some memorable act, such as paying with pennies, and they were later asked to look at photographs to identify that person. They were only correct 34-48% and incorrect 34-38% of the time. This means that identification of a person may be incorrect and they may be wrongly convicted of the crime.
When eyewitnesses are asked to pick the offender out of an identity parade, they may feel pressured to pick a person out even though they may not be 100% sure they have chosen the correct suspect.
Problems such as these were also found in a study by MacLin and colleagues who found that out of 62 convicted offenders had their conviction reversed when DNA evidence later exonerated them, 52 of those had been convicted using eyewitness testimony alone. This means 52 innocent people in jail because of an eyewitnesses mistake.
But by putting in stringent frameworks, it is possible to reduce the number of incorrect identifications. Several procedures have been put into everyday practice by police to reduce the possibility of incorrect identification of a suspect. Measures such as the officer not knowing who the suspect is so as not to influence the witness, the witness being told the offender may not be in the lineup, having similar looking people used in line ups, and no feedback to be given to the witness, can all help to reduce inaccurate information.
Both the quantity and quality of information drawn out from witnesses and suspects is of great importance. Therefore, a comprehensive semi-structured interview technique has been proven to improve the quantity and quality of information from both suspects and eyewitnesses. The Cognitive Interview contains several factors: Establish rapport, listen actively, encourage spontaneous recall, ask open-ended questions, pause after responses, avoid interrupting, request detailed descriptions, encourage intense concentration, encourage the use of imagery, recreate the original context, adopt the rememberers perspective, ask compatible questions, encourage multiple retrieval attempts.
In an attempt to make this simpler so it could be adopted into everyday policing practices, the PEACE interview was developed. PEACE is an acronym where all of the letters stand for something to be done. This summarizes the main components of the interview to Planning and preparation, Engage and explain the purpose of interview and process, Account – free recall, Clarify challenge and conclude, Evaluate – new lines of enquiry?
When interviewing suspects, it is important to acknowledge that they may not always be telling the truth. Interview methods such as the Cognitive Interview and PEACE framework can help in getting as much information as possible.
It is suggested that officers be as open and honest as possible with any evidence they have against a suspect as this makes them more likely to confess. However, that information may not always be present. In cases such as this, Investigative Psychologists have developed various ways of telling when someone is lying.
In the past, detectives have used polygraphs, or lie detectors, to detect deception. These work by measuring physiological arousal, in other words, their emotional response to a question. However, some studies have found these not to be 100% accurate.
There are several incorrect stereotypes linked to spotting a liar. Many people, including police officers, believe that not looking someone directly in the eye, or fidgeting whilst talking are signs the person is lying. These are popular, but incorrect, ideas of what liars do. By using carefully researched markers of deception, the accuracy rates in spotting a liar can be increased significantly.
Another area that Investigative Psychologists have helped police is identifying where a criminal is likely to live. This is called geographical profiling. This grew out of work Professor Canter did with Detective Constable Rupert Herritage in the 1990s. The basis of this is mapping out crimes which occur in a series. Offenders have shown to behave in similar ways with the distance they travel to offend. They will consider where or not they know the area well, how they might get back after the crime, whether they will be recognised whilst committing the offences. This is a major aspect of Investigative Psychology and will be discussed in its own video.
Whether we are behaving in criminal or law-abiding ways, we are most confident in areas we know well. We form mental maps of the areas surrounding us. We tend to underestimate distances in areas we know well and underestimate distances in unfamiliar places. By using a complex computerised system, in this case, it is called Dragnet, we can input where on the map the crimes occur and as a result where the most likely home base of the offender is going to be.
The final way in which Investigative Psychology can be applied to policing is matching some offending actions to the characteristics of the person who is likely to have carried them out. In essence, this is creating profiles of offenders. When investigative psychologists infer the offender’s likely characteristics based on the crime scene actions it is based on knowledge from several disciplines such as criminology, sociology, clinical psychology, child psychology, criminal psychology, social psychology, and organisational psychology.
As has already been discussed, it is important to match the right types of activities to the right level of characteristics. The use of structured methods to gather, analyse and report these findings are of utmost importance. Psychological researchers use complex statistics to enhance the everyday activities of police, including creating profiles, to explore and explain their findings. What we must be mindful of is that this information needs to be translated in a way which is understandable and accessible to everyone. It would be useless to present complex statistical findings to the police and recommend policy or procedure because they may not always understand it.
So when we present findings of profiles, it is important to keep it as simple and understandable and applicable as possible. In doing this, investigating officers and police will be able to easily integrate these findings into their everyday procedures.
