A pin with a portrait of Mireille Knoll is seen on a man's jacket during a gathering, in Paris, France, March 28, 2018. Mireille Knoll, 85, was found dead with 11 stab wounds at her apartment in a working-class district of Paris on Friday. The apartment was set ablaze after the attack and her body badly burnt. Police suspect that Knoll's Jewish religion was a motive for the killing. REUTERS/Gonzalo Fuentes