White march held in tribute to slain French couple A white march is held Saturday in Mantes-la-Jolie, France, to pay tribute to Jessica Schneider, an administrative officer at the city's police station, and her partner, police commander Jean-Baptiste Salvaing, who were knifed to death this week at their home in Magnanville by an extremist pledging allegiance to the Islamic State group. IMAGES AND SOUNDBITES