While my thought go with the family of the victim, sadly, when an attack like this takes place, on both sides people will use religious belief as the reason for and against the attack; while I deplore such acts of murder, in turn, and too often, people will hate a particular group because of their religious beliefs - an islamist terrorist hides behind his/her religion as the reason why innocent people should die, but almost everyone else tars every Muslim with the same brush. Does that mean all Spanish people should be loathed because of the Basque separatists, or the Irish people because of terror groups like the IRA?
Hatred of Muslims is not a recent thing, or because of 9/11: you should read Edward Gibbon's History of the Decline and Fall of the Roman Empire, especially his volume on Mohammed and the Rise of the Arabs.
These people are murderers, period.