If (and I emphasize IF) he has some condition such as clinical Schizophrenia, they did not "cause" it. That is a terrible and unfair myth that somehow mental illness is "caused" by bad parenting, or is just some character flaw in a person. Nothing could be further from the truth. I come to this opinion as the coordinator of a family education program in my state for the National Alliance on Mental Illness (NAMI) to educate family members who have loved ones with serious mental illnesses. Schizophrenia (if that's what he has, and it sure seems like it) is a result of very real physical differences in the brains of those affected. No one asks to be affected by such terrible mind diseases, but it can happen to the best of families. It can happen at any age but schizophrenia most often shows up in young men in their late teens or early twenties. We have some friends with a 20-something son who was on top of the world and had an appointment to the Air Force Academy. He was in his second year when he began getting symptomatic and was ultimately removed from the Academy and later diagnosed with severe schizophrenia. This is a good, loving family and their son had, up till this time, been a normal happy, healthy young man. His illness was not a result of anything his parents did or didn't do.
Schizophrenia, particularly that involving paranoia, involves a disconnect from reality.
Loughner asked his friends to forgive him for the forthcoming assasination. This is not the behavior of a schizophrenic.
Jared knew what he was doing.