MANN ET AL - police officers ability to detect lie
Aim: Police officers ability to distinguish truth and lies during interviews with suspects.
Procedure: The pp's task was to judge the truthfulness of people in real life police interviews. At the begining they filled a questionair out about thier experiance in detecting lies. They then saw video clips of suspects. After watching the clips they had to indicate whether it was a lie or the truth and how confident they were with thier decision.
Results: Police officers were 66.2% accurate at detecting lies and 63.6% accurate at detecting truth.
Conclusions: Police officers are good at detecting lies however we needed a control of normal people in order to test reliablity.
INBAU ET AL- nine steps of interrogation
Chance to shift blame-
Never allow the suspect to deny guilt-
If suspect cries, infer guilt-
Pose the 'alternative question'-
Admit guilt in front of witness-
Doccument suspects admission-
GUDJOHNSSON ET AL- a case of false confession
Aim: To doccument a case of false confession.
Procedure: 17 year old youth accused of two murders. He was arrested because of inconsistencies in accounts of his movements during an earlier routine enquiry. Denied access to solicitor and interviewed for 14 hours leading to his confession. No forensic evidence linking him to crime. After a year in jail he was released because someone else had confessed.
Conclusions: Clear case of a false confession, he gave into the pressure he was put under in the interview to escape the situation.