People including French activist and Nazi hunter, Serge Klarsfeld and his wife Nazi hunter, Beate Klarsfeld, attend a gathering, organised by the CRIF, in memory of Mireille Knoll, 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