According to The Associated Press, the mother of the 26-year-old Oregon gunman who killed nine and injured nine "told investigators he was struggling with some mental health issues." Yes, he was.

Neighbors have described Christopher Harper-Mercer as an anxious, alienated young man. His mother, Laurel Harper, appears to have written in online forums about his mental and social struggles.

It's a profile so familiar it's cliche. Dylann Roof, the "quiet" 21-year-old white supremacist accused of murdering nine people in a Charleston, South Carolina, church in June, was similarly disturbed. And, of course, Adam Lanza, the 20-year-old who in 2012 sprayed gunfire through the classrooms of Sandy Hook Elementary School, had all the markings of the agonized loner who seeks catharsis by making others suffer horribly in turn.