The place of expert evidence in French criminal courts

Expert evidence is produced by having recourse to the forensic sciences. It helps to decide of the innocence or guilt of the judged by jurors of the French courts. It is necessary to study if those accused do have at their disposal enough guarantees when forensic sciences are used in criminal trials. Accused should at least benefit by two guarantees when expert evidence is used in front of French criminal courts: first the expertises are executed by specialists and so should be reliable: then, expertises should be normally controlled by the occasional magistrates (i.e. jurors). The reliability of expertises depends on the personal qualities of the expert (intelligence, professional conscientiousness, ability) and the method used for the valuation. Concerning jurors control on expertises, the study tries to show that jurors are not able to appraise expert evidence, because of their ignorance relating to forensic sciences. In fact, their conviction is determined by the pressure exerted on them by public opinion and by the impressions created in court by experts. All these remarks lead to conclude that it is necessary to suppress the jury institution in French criminal courts and to replace it by professional magistrates specialized in criminal law and forensic sciences.