We have studied every mass shooting since 1966. Here’s what we’ve learned about the shooters
https://www.latimes.com/opinion/story/2019-08-04/el-paso-dayton-gilroy-mass-shooters-data "First, the vast majority of mass shooters in our study experienced early childhood trauma and exposure to violence at a young age. The nature of their exposure included parental suicide, physical or sexual abuse, neglect, domestic violence, and/or severe bullying. The trauma was often a precursor to mental health concerns, including depression, anxiety, thought disorders or suicidality."