These ponderings attempt to let themselves be appropriated by the event. (Beiträge zur Philosophie (Vom Ereignis), Martin Heidegger, 1936–38/1989)
https://en.wikipedia.org/wiki/Peter_F._Langman
https://www.washingtonpost.com/local/the-twisted-minds-of-school-shooters-and-the-anguished-man-who-studies-them/2016/06/30/44987378-2e4e-11e6-9b37-42985f6a265c_story.html
https://www.theguardian.com/world/2016/jul/23/munich-shooter-why-kids-kill-book-psychologist-peter-langman
https://www.psychologytoday.com/intl/blog/keeping-kids-safe
