A French police officer who shot and killed a 17-year-old driver will be investigated for voluntary homicide, following two days of fires and violent protests that injured scores of officers, officials said Thursday. Some 40,000 police officers will be deployed overnight to quell violence that engulfed cities and towns in the wake of the shooting.

The killing of 17-year-old Nahel during a traffic check Tuesday, captured on video, shocked the country and stirred up long-simmering tensions between young people and police in housing projects and other disadvantaged neighborhoods around France. Protesters set cars and public buildings ablaze in Paris suburbs and unrest spread to some other French cities and towns.