If you want to know what causes school shootings, follow the money. Journalists know coverage of school shootings causes copycat shootings. But they cover those stories because it increases ratings. Who is controlling them? http://www.bbc.com/news/world-us-canada-34385059 Research shows that, in fact, mass shooters may be more likely to act when there has recently been a high-profile mass killing, a model more attune to viral infection than pure copycat.