Those who are suspected of taking part in crime will often lie. A suspect will rarely admit to their part in a crime when they are first interviewed. Police officers are trained in interviewing techniques which help to draw as much information out of the suspect as possible. These interviewing techniques also help to identify when suspects are lying.
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.
In the past, detectives have used polygraphs, or lie detectors, to detect deception. These work by measuring physiological arousal, in other words, their level of physical arousal in response to a question. The person being interviewed is fitted with a device on their finger to measure sweat rates. They also have a blood pressure cuff and two rubber straps around the chest and abdomen to measure breathing.
However, some studies have found these to be unreliable and only about 50% accurate. Although this didn’t seem to bother Jeremy Kyle much! The polygraph measures physiological responses to questions but there are no proven physiological responses associated with liars. The machine is measuring stress levels. It is believed that when people are lying it causes more stress and as such can be detected by the machine.
You might think that police officers and detectives are much better at telling when people are lying than the rest of us. However, several studies have found that law enforcement officials are no better at spotting liars than everyone else. There is about a 50/50 chance of getting it right and spotting a liar.
As a result of numerous studies within psychology, an interview technique was developed called the cognitive interview. This interview technique was primarily developed to interview witnesses and victims of crime. The interview technique uses several different types of retrieval cues and encourages the interviewee to remember all the events that occurred.
Cognitive interviews reliably enhance the process of memory retrieval and have been found to elicit memories without generating inaccurate accounts. Further research has established that this interview technique allows those who are lying to be identified more easily.
The Cognitive Interview is grounded within psychology and contains several important factors within an interview. The interviewer should establish rapport and listen actively to what the person is saying. The interviewer should encourage spontaneous recall of information and ask open-ended questions. They should ensure that they leave a pause after each response and should avoid interrupting. The interviewer should also request detailed descriptions and encourage intense concentration throughout the interview. The use of imagery should be encouraged and the person should also be encouraged to recreate the original context in their mind. Questions should be asked from the perspective of the person remembering the information and compatible questions should be asked throughout. Finally, multiple retrieval attempts of the information should be encouraged.
For the cognitive interview to be adopted into everyday policing practices, the main components of the cognitive interview were summarized and as a result, the PEACE interview was developed. This interview technique is a conversational approach to gathering information rather than confrontational.
PEACE is an acronym where all of the letters stand for something to be done. This P stands for Planning and preparation. The interviewer should know who they are interviewing and have a set of questions already prepared. The E stands for Engage and explains the purpose of the interview and process. The interviewer should explain what information they need and why they need it. The person being interviewed should be treated like a person rather than a suspect and the language should be kept simple. A stands for Account – the interviewer should allow free recall. Open-ended questions will allow for more information to be obtained. The C stands for Clarify challenge and conclude. The interviewer should explain what happens next and check that they have all the information they need. Finally, the E stands for Evaluate. The interviewer should evaluate their performance. They should evaluate what information was gathered and decide whether any actions need to be taken.
By using these principles during an interview, both the quantity and quality of information is enhanced. It has been found that the PEACE interview helps those giving truthful accounts of an event to remember all of the relevant information. The technique also makes it much more difficult for a liar to continue to lie. By asking about all aspects of the event in several different ways, the liar is much more likely to contradict themselves.
