When a crime, misdemeanour or traffic accident is detected, the officers or agents of the criminal investigation department must carry out the checks provided for in article L. 234-1 of the Highway Code andarticle L. 4274-14 of the Transport Code on the person of the alleged perpetrator in order to establish proof of the presence of alcohol in his body when it appears that the crime, misdemeanour or accident was committed or caused under the influence of alcohol. These checks are compulsory in all cases of crimes, offences or accidents resulting in death. In all cases where they may be useful, they are also carried out on the victim.