A caricature that many Muslims considered blasphemous prompted a debate over free speech and a massacre at the offices of a Paris magazine.A caricature that many Muslims considered blasphemous prompted a debate over free speech and a massacre at the offices of a Paris magazine.Read MoreCartoons and Cartoonists, Freedom of the Press, Deaths (Obituaries), Kurt Westergaard, Denmark, Mohammed, The Prophet of Islam, Charlie Hebdo, Jyllands-Posten, Demonstrations, Protests and Riots, Assassinations and Attempted Assassinations