TL;DR; 1. > ...experienced early childhood trauma and exposure to violence at a young age... often a precursor to mental health concerns 2. > ...practically e

TL;DR; 1. > ...experienced early childhood trauma and exposure to violence at a young age... often a precursor to mental health concerns 2. > ...practically every mass shooter we studied had reached an identifiable crisis point in the weeks or months leading up to the shooting. 3. > ...most of the shooters had studied the actions of other shooters and sought validation for their motives. 4. > ...the shooters all had the means to carry out their plans.