Article here. Excerpt:

'From those mass shooters who have attacked the innocent before, we know it’s a specific strain of anger — deep, repressed, biblically vengeful — felt most commonly by young men, almost always white, who report feeling alienated, dispossessed, misunderstood, victimized and all too often rejected by women.

Their chosen outlet is the mass slaughter of innocents, carnage at places the rest of us once deemed safe — schools, hospitals, places of work and worship, concerts, carnivals — all meant to hold us hostage, in fear of the next reprisal we’re not responsible for and won’t see coming.'