The sources of violence are bad human judgment, call it evil. Evil can penetrate into human body via many means, including religion. Like the guard on duty who was supposed to protect his master actually killed him. Was his a religious or evil motive? Islam does not support violence, but in this case we can say evil superseded his religion. Bad religious thought is also evil and people might say that religion has fuzzy edges. I think it is not. It is man’s mind alone, not religion that lures him to evil way. What is the difference between blistering zealot and a cool Moulvi sharing same religious idea. It is evil.