HB:
I'm not going to presume to speak for OAM, but, in response to your questions, here are my $.02.
is every child that had a horrible childhood allowed to grow and turn into a serial killer?
No, but some do, and therefore we have a vested interest in children not having to live horrible lives.
is every woman that’s battered by a man allowed to shoot him?
No, but considering the circumstances, it might be a defense at a murder trial.
At what point do you recognize that a criminal, regardless of root causes, who is being violent bear some responsibility for what happens to them at that point?
We all bear primary responsibility for our actions, including those of us who suffer from those "root causes." But we should recognize that it's easier to see that when we were raised in reasonably stable family environments, when we didn't have to wonder if mama was going to have any food to fix for dinner, and when we saw a justice system that seemed to deal reasonably with people like us.
Are you saying that systemic racism gives people a free pass? Because trust me when I tell you that’s what it sounds like to a lot of people.
No free passes. But we need to fix the institutional problems that make things worse than they need to be for poor people in general, people of color in general, and poor people of color in particular.
I'm an 18th-century liberal, which made me a late-20th-century conservative. What it makes me in the 21st century, I don't know, since the Trumpists seem to have stolen the "c" word from people like me.
I believe that free markets beat government economic controls 99 and 44/100ths percent of the time. I believe that the free enterprise system has lifted far more people out of poverty than government anti-poverty programs have. (Just look at poverty rates since LBJ's War on Poverty began.) But it's been 155 years since slavery was abolished, and black people have not been treated the same as white people by the federal government in all that time. They've either been treated like the dirt beneath our feet or as children who have to be looked after by paternalistic Uncle Sugar, or both at the same time. And it hasn't been greatly better even for whites among the working poor.
I think that every sensible person wants to see everybody have the road open for him or her to pursue happiness, not have the federal government (or state governments either) dictate winners and losers from birth.
We're not supposed to have a ruling class born booted and spurred, nor are we supposed to have a servile class born to a life of drudge-labor or government welfare programs.
Finally, people born into the servile/welfare class don't grow up with the same trust in the law and its enforcement officers that I did and I presume you did.