What do you mean by bad parenting? What habits of bad parenting make someone willing to cross the line and become willing to massacre as many people (perhaps perceived as those who have done the shooter wrong, as is true in some of the school cases, perhaps innocent strangers) as possible?
I also suspect there are some cases (Columbine AFAIK) where they were no obvious signs of bad parenting.
This seems to just raise further questions.
