When I see a "news" story so devoid of any pertinent information about how the "accident" occurred, things like who fired the shot, was it self-inflicted, what was the intended target, who were the other persons, what were these other person doing at the time, was alcohol involved, were drugs involved or anything at all that would provide the needed information, I have to suspect that there is more behind the story. Heck the story does not even mention the time the "accident" occurred. Was it 3:00 P.M. or 3:00 A.M. or what actual time it happened. Also missing is who is investigating the "accident" or virtually any detail a reasonably competent high school newspaper reporter would include.
There are "accidents" that upon investigation lead to negligence, murder or suicide being the actual cause. There simply are no details provided in the story to rule out any of these.