Did religion in general kill these folks, or was it, perhaps, a particular faith?
There's an interesting question.
Most criticize extremist sects of Islam for their violent methods of enforcing Sharia law, the infamous "sword verse" against Christians, death for apostasy, etc....but I believe the majority of Muslims inherently feel this behavior is wrong.....they know it is. They concentrate on the positive aspects of Islam. Others criticize the church of Rome because of the crusades, but what really happened in this situation? Did the church order random murder?
Could it be it's neither the generalized concept of "religion" nor a specific "faith" and just misguided people choosing to commit evil?