The profile of the young male mass shooters share a 3 element matrix.
1 Awash in grandiose towering narcissism
2 Immense amount of insecurity and grievance
3 An adolescense that believes the world has not respected them or paid them their due.

The young alienated losers have an anger that builds up that the presence of an AR 15 is a shooting waiting to happen.

MSNBC