I didn't find much but here is some: * http://cad.sagepub.com/content/48/1/46 http://cad.sagepub.com/content/48/1/46 * http://books.google.rs/books?hl=en&lr=&

I didn't find much but here is some: * http://cad.sagepub.com/content/48/1/46 http://cad.sagepub.com/content/48/1/46 * http://books.google.rs/books?hl=en&lr=&id=3B4lTTZE58oC&oi=fnd&pg=PR9&dq=copycat+effect&ots=vfNvk73kTl&sig=1S0gp41Ne8E4SSFUDr9NW9HqI50&redir_esc=y#v=onepage&q&f=false http://books.google.rs/books?hl=en&lr=&id=3B4lTTZE58... * http://en.wikipedia.org/wiki/Social_contagion http://en.wikipedia.org/wiki/Social_contagion They are cited as references on this page: *http://en.wikipedia.org/wiki/Copycat_crime http://en.wikipedia.org/wiki/Copycat_crime As for other evidence, you'd need to look at crimes and if there is a large number of similar attempts of violence (not necessarily school, but overall mass shootings), grouped around highly prominent cases covered by media. That kind of research and evidence is sadly outside my scope. I'm not sure where you'd find sources, nor how to process them statistically correct.