PARIS, FRANCE - APRIL 20: French security forces cordon the area after a gunman attack, killing a police officer at Champs Elysees in Paris, France on April 20, 2017. One police officer was killed and two others were seriously injured Thursday when a gunman opened fire at a police patrol on the famous Champs-Elysees boulevard here, according to the Interior Ministry. (Photo by Raphael Lafargue/Anadolu Agency/Getty Images)