This measure consists of an examination carried out by a doctor who is a specialist in mental illness. The results of this examination may constitute grounds for non-accountabilty or diminished responsibility of the person concerned. In such a case, a person who, at the time the offence was committed, was suffering from a mental or a neuropsychological disorder which caused him or her to lose all judgement or control of his or her actions, is not criminally responsible. In addition, a person who, at the time the offence was committed, was suffering from a mental or a neuropsychological disorder which impaired his or her judgement or impeded the person's control of his or her actions remains punishable; however, the court will take this circumstance into account when deciding on the sentence and on the sentencing regime.
Under French law a distinction is made between examination and expert assessment. The public prosecutor can order psychiatric medical examination in case of flagrante delicto (Art. 60 Criminal code of procedure) or preliminary investigation (Art. 77-1 Criminal code of procedure). As for the investigating judge, he may request a psychiatric expert assessment under article 81 and article 156 to 169-1 of the French criminal code of procedure.
Despite this semantic distinction between expertise and examination in the criminal code of procedure, the French Court of Cassation ruled that article 77-1 gives the public prosecutor acting in a preliminary investigation the power to entrust any qualified person with technical or scientific missions of the same nature as those that can be entrusted to experts by the investigating judge under article 156.