Slap and Outlaw09,

Perhaps this short Scientific American article can help: 'The Science of Mass Shooters: What Drives a Person to Kill? (sub-title) There is no template for the path to violence and rarely can a single cause explain any one atrocity':http://www.scientificamerican.com/article/the-science-of-mass-shooters-what-drives-a-person-to-kill/?

It is a quick resume of some research and cites Professor Mia Bloom in particular:
We need to get rid of the bystander effect..We need to find a way that if someone says they are planning to do something, that there are safe mechanisms for the individual to report without themselves becoming a suspect or a person of interest. We need to come up with a way of separating the wheat from the chaff as far as people who are serious.
I note the actions are a mixture of personal, institutional and state surveillance of online activity. Sadly IMHO it would overwhelm law enforcement and intelligence with too much data, let alone "false flags". Plus IF mental health is the focus is that is politically acceptable.