Source: http://edition.cnn.com/2016/07/23/europe/germany-munich-shooting/
(CNN) The teen gunman who killed nine people in a shooting rampage in Munich on Friday was a mentally troubled individual who had extensively researched spree killings and had no apparent links to ISIS, police said.
Condolences to the victims of the Munich shooting.
The next generation of shooting prevention technology lies in psychology, to detect such shooters before they even act. According to Wikipedia, Gun legislation in Germany is considered among the strictest gun control in the world, yet the attacker (Ali Sonboly) managed to get hold of a gun (this fact seemed yet to be explained in the news).
Dr Peter Langman, the world expert on this matter, has written such a book: Why Kids Kill: Inside the Minds of School Shooters. There are some patterns that can be detected, maybe Big Data can help.

According to Dr Langman, “The end of the book will not present anything like: A + B + C = School Shooter. The subject is too complicated for that, and there is much that we do not know. Nonetheless, I believe this book will shed light on a phenomenon that, despite massive media coverage, has remained mysterious.”.
Another interesting fact found in Dr Langman’s book is that attackers are not typically loners, unlike what mainstream media usually claims. Dr Langman states that, “A popular sound-bite view of school shooters is that they are loners, a status seen as a contributing factor in their rampages. This is inaccurate. Whereas 9 out of 10 of the shooters we discuss were depressed, only 1 out of 10 was a loner. The others all had friends and acquaintances with whom they engaged in a variety of social activities.”
Overall, review of Dr Langman’s book is highly positive. Definitely useful for teachers in USA to read.