I hope not but, I bet there is more to this than we know. If he really was defending his mother then why would she let him take the fall instead of letting her husband rightfully get arrested? Possible that more info will come out about this in the next few days that will either further implicate him or excuse him...
It's the world we're living in. If they arrive at the scene, someone is going to jail. If Laremy's stepfather has a busted up face and no one else is showing signs of physical harm, Laremy is going. Perhaps his stepfather was arrested as well though.
40 years ago it would've probably just been "well, if he does it again, kick his ass a little harder. Y'all have a nice day"