As sad as this situation is, I believe 10-20 years in prison would be more than enough.  Nathanial was, for all practical purposes,  a teenager captive to a dysfunctional family and constant barrage of his father's anti-social beliefs.  The world around him came crashing down.  His young mind weighed all the "lessons" he'd been subjected during his formative years.  "Stand up for your family."  "Stand up for your culture."  "You and your people have been enslaved."  "Be a man."  "Stand up to 'the man'". Get the picture?  Provided he isn't diagnosed with psychopathy,  the best outcome would be a remorseful and rehabilitated Nathanial's eventual return as productive member of society.  This "special verdict"  flies in the face of "all men are created equal" and for all practical purposes, creates a class of citizens who are "more equal than others". Murder is murder.  Laws like this tie the hands of judges when making decisions...especially when considering extenuating circumstances.