You are right. The two kids who started all this school shooting business in Colorado in the ‘Nineties were white middle-class kids from a two-parent family.
There has never been much investigation of their home life etc. as far as I know.
http://www.columbine-online.com/columbine-parents-killers-eric-harris-dylan-klebold.htm
The writer is a lefty, so be aware.
If I remember correctly they were both taking some kind of brain medication (Ritalin, or some similar drugs). Having an atheistic worldview (remember they targeted some Christian students) was probably a bigger factor, but I believe a lot of these mass shootings have a common thread of the instigators having had their brains mucked around with various psychotropic drugs.
***...were white middle-class kids from a two-parent family.***
As was Kip Kinkle, Not poor,nice area, nice house, nice family life, till he murdered his parents, shot up a school and was captured by the police while yelling at them,..”KILL ME! KILL ME!
Scene from TOMBSTONE:
Wyatt: What makes a man like Ringo do what he does?
Doc: He has a big hole through his middle and he can not kill enough or steal enough to fill it.
Wyatt: What does he want?
Doc: Revenge for being born.