What are the precipitating factors found in those that commit acts of mass violence? How can we use that information to prevent and mitigate future acts of mass violence?

Preventing and mitigating acts of mass violence

This is for a thesis proposal on Acts of Mass Violence…my thesis questions are:

1. What are the precipitating factors found in those that commit acts of mass violence?
2. How can we use that information to prevent and mitigate future acts of mass violence?