I'm not suggesting that they are not Muslims. I just find statements like the one about the "Islamic names" to be problematic. If one is only going by the names, that could very well be an erroneous assumption. There have been terrorist attacks in the Middle East that have been committed by Christians, for instance. And I have been able to find at least one person with the name Khalid who is an Iraqi Christian...

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However, if the suspects themselves have said that they are Muslims, we are probably more safe in assuming that they are in fact Muslims.