"(Serial killers do not attend church. None of them have or do."
Actually, that statement is far from true. Many churches under many guises (all in the name of their biblical god) have been responsible fro some incredible attrocities. So not only have mass murderers attended church but they have also held the highest offices in these churches.
People tend to use false moral pedestals (churches) to hide behind to commit crimes.
History is full of evidence.