Article R15-33 of the French Code of Criminal Procedure
Officers and judicial police officers belonging to search brigades, territorial brigades organised or not into brigade communities, motorised brigades of the departmental gendarmerie and surveillance and intervention platoons of the departmental gendarmerie referred to in 1°, 3° and 4° of Article R. 15-24 are competent to operate on all lines, stations, stops and corridors assigned to collective passenger transport in their department of assignment and in neighbouring departments.