As is often the case in the wake of an individual committing a seemingly inexplicable act of violence, warning signs are coming to light that, if recognized earlier, might have prevented the murder-suicide of 150 passengers and crew aboard Germanwings Flight 9525 by Andreas Lubitz. Among these signs are persistent mental health issues, the severity of which Lubitz appears to have attempted to hide from his employer, and comments suggesting an intention to take some grand action that would make him famous. These warning signs inevitably raise questions about why the violent act was not prevented.
Tinsley, Herbert and Cory Davenport. 2015. "Discussion Point: Insider Threat in the Aviation Industry." START (April). https://www.start.umd.edu/news/discussion-point-insider-threat-aviation-industry