If history has any telling, most of these mass killers are angry, alienated, and resentful. They often turn out to be injustice collectors.
That has been the case with Nikolas Cruz, Adam Lanza, Seung-Hui Cho, Dimitrios Pagourtzis, Eric Harris and Dylan Klebold, Elliot Rodger, Devin Kelley, Omar Mateen, Stephen Paddock, and 9/11 Terrorists.
This also applies with Yoselyn Ortega, Jodi Arias, Betty Broderick, Michelle Carter, Lori Drew, Casey Anthony, Karinthya Sanchez Romero, Susan Smith, Eliza Baker, Gertrude Baniszewski.