Psychology brings justice: the science of forensic psychology

In this paper the focus is on one aspect of forensic psychology: the development of psychological instruments, a social psychological model and assessment procedures for evaluating the credibility of witnesses and police detainees during interviewing. Clinically grounded case work and research has impacted on police interviewing and practice, the admissibility of expert psychological testimony and the outcome of cases of miscarriage of justice. After describing the research that laid the foundations for advancement of scientific knowledge in this area, a brief review is presented of 22 high-profile murder cases where convictions based on confession evidence have been quashed on appeal between 1989 and 2001, often primarily on the basis of psychological evidence. The review of the cases demonstrates that psychological research and expert testimony in cases of disputed confessions have had a profound influence on the practice and ruling of the Court of Appeal for England and Wales and the British House of Lords. The cases presented in this paper show that it is wrong to assume that only persons with learning disability or those who are mentally ill make unreliable or false confessions. Personality factors, such as suggestibility, compliance, high trait anxiety and antisocial personality traits, are often important in rendering a confession unreliable. Future research needs to focus more on the role of personality factors in rendering the evidence of witnesses and suspects potentially unreliable.