Family Values

Mitt Romney on violence and values in American families:
But let me mention another thing, and that is parents. We need moms and dads helping raise kids. Wherever possible, the — the benefit of having two parents in the home — and that’s not always possible. A lot of great single moms, single dads. But gosh, to tell our kids that before they have babies, they ought to think about getting married to someone — that’s a great idea because if there’s a two-parent family, the prospect of living in poverty goes down dramatically. The opportunities that the child will — will be able to achieve increase dramatically. 
So we can make changes in the way our culture works to help bring people away from violence and give them opportunity and bring them in the American system.
For what it's worth, each of these guys was raised in a two-parent family:
Dylan Klebold (Killed 8)

Eric Harris (Killed 8) 
Jared Loughner (Killed 6)
James Holmes (Killed 12)

This man, however, was raised by a single mother, who occasionally collected food stamps.
Barack Obama, 44th President of the United States