A 14-year-old boy who shot dead an 11-year-old friend on an East Coast farm acted with recklessness rather than deliberate intent, a judge said in the High Court in Gisborne on Tuesday.
Justice Miller sentenced the boy, who was 12 at the time of the shooting in July last year, to 20 months in jail.
He said it was a crime of quick and powerful anger following a trivial squabble between two boys over a planned hunting trip.
"Your behaviour was both very aggressive, and extraordinarily reckless. You knew right from wrong, and you differed from most children in that you were very familiar with the rifle, and what it could do.
"It is not unreasonable to expect of you that you should have handled the weapon, if you handled it all, with appropriate care."
In October, the teenager - who was originally charged with murder - pleaded guilty to manslaughter.
Justice Miller ordered permanent name suppression for the boy and his father, whom he sent to jail for two years for perverting the course of justice by persuading his son and an 18-year-old to give false statements to the police. The father earlier pleaded guilty.
Justice Miller described the man's actions of trying to cover up what actually happened on the farm as being very negligent, reckless and irresponsible.
But he said permanent name suppression for the boy and his father would give the teenager a better chance to be rehabilitated and re-integrated into society once he left prison.
A number of the victim's family gave impact statements to the court in which they said they were still very angry that such a young person could be at risk from a rifle that was left unsupervised.