The Problems and Limits of Fair Credibility Assessment in German Criminal Law. Discussion about Systematization and Improvement of the procedure of Credibility Assessment

The role of an expert in a criminal proceeding is disputable. On the one hand, the expert’s “monopoly” is criticized, namely the fact that the judge’s responsibility is reduced because they have to trust in the expert’s specialist conclusion. On the other hand, the expertise process is analyzed as a whole by psychologists and non-experts not only from the methodical point of view but also in terms of its contents. The diagnostic process of the credibility assessment requires an enormous cognitive accomplishment of the expert. This is the result of the complexity of the expertise task because there exists no valid theory of credibility, which could link psychologically meaningful constructs in a universally valid law. For that reason, experts have to adapt themselves to a variety of small laws (so called indicators). Added to the high complexity of the credibility assessment there are also high demands on the court in respect of the quality of the expert. On the one hand, the expert has to observe the legal and ethical frameworks and act in a structured and scientific way. On the other hand, his or her way of thinking has to be flexible and self-critical. The problems of the credibility assessment raise the question of how exactly the expert assessment proceeds and where do its borders lie. Then the identification of its borders can contribute to more transparency and with that to the improvement of the expert assessment’s quality. This article deals not only with the difficulties of credibility assessment but also with the possibilities of the systematization and improvement of the credibility assessment’s procedure. First of all, the judge’s expertise and the expert’s position in the criminal proceeding are explained. Afterwards the complex diagnostic process of the credibility proceeding is explained. Then the author explains problems and limite of the credibility proceedings and their consequences within the practical application of the credibility proceeding. Finally, several possibilities that can contribute to improvements in quality are discussed.