I don't think ethnicity had anything to do with it.

On CNN I saw pictures that Gill had taken of himself holding a rifle and a knife. The most notable thing about him was his utter lack of presence - the emptiness of his eyes. Here, they said, is a nebbish. A toxic nebbish, certainly, but still a nebbish.

Apparently he spent much time on net sites glorifying his fellow toxic nebbishes, Eric Klebold and Dylan Harris, the Littleton, Colorado murderers. Finally he decided to become "somebody" by following in their footsteps.

Society needs to address the processes by which malicious strangers identify and manipulate weak people like Gill.