From the article:
[Deputies] were told that the boy, who is almost 13, and his father had an argument about the son recently getting in trouble in school, police stated. It was apparently exacerbated because the boy’s mother and father had recently gotten back together after a long separation.
Police stated that the son threatened the father with the knife, then put it down but picked up a small caliber rifle. The father apparently took the rifle away after a small struggle.
The boy was arrested on charges of domestic assault and assault with a weapon. He was lodged in the Allegan County Youth Home.
Every gun in the hands of a child must first pass through the hands of an adult.