My opinion is that the mother in this situation is largely responsible for this outcome. She failed to protect her child. I know she is seventeen, and she clearly didn't have any family members that stepped in and said "you are in over your head and someone is going to get hurt". I have empathy for her age and lack of a support system, but she made a choice to keep her child and not place him for adoption or terminate the pregnancy. She took on the responsibility of protecting her child.
This was not a sudden and unpredictable act of rage.
I wouldn't keep a puppy in my home if I thought my psycho boyfriend would torture and kill it to make some psychotic point. She had options other than skipping court and waiting for the next attack to come. Her child is the one that had no options.
Everyone screams about the children, the children come first, we have to do something.... but if anyone suggests that a mother who has a made compounding bad decisions be held accountable along with her boytoy and that is just out of the question. It is victimizing the victim... NO it isn't. These women are making choices that serve their own wants/needs/ego. If their priorities put themselves before their child than you have to motivate them with the possible loss of freedom. Motherly instinct in and of itself is clearly not enough.
And that is not to say that I don't understand that sometimes horrible things like this happen and there was nothing the mother could have done. Some of these guys hide it well and then snap one day. Those are not the situations I am talking about. I am talking about a child that had a gun held to his head a MONTH ago. A month worth of days that someone could have made a choice that was actually in the kids best interest.