What was Colin Gray's role in the school shooting tragedy?

Colin Gray's negligence contributed directly to the school shooting tragedy by purchasing an assault rifle for his son, Colt. As emphasized by a victim's family member in court, "Because of his stupidity, he bought his son an assault rifle. Not a BB gun, an assault rifle." This act of "sheer irresponsibility" by Mr. Gray is central to the unprecedented charges he now faces - charges typically reserved for perpetrators rather than parents. His decision to provide a dangerous weapon to his troubled teenage son ultimately led to the loss of four lives and deep trauma across the community.