I would opine that the treatment of boys is so demeaning today,  wholly supported by the feminist public education system's war on boys,  that results like this one will be more common as time goes on.

A century of education research says boys are emotionally,  mentally, and physically behind girls of the same age until after puberty.  As much as two years behind by age 6.   So expecting equal results with equal treatment in the feminist driven  education system sees 60% of university grads now female, and 40% male,  by biological gender at birth.  50% more grads should be a frightening statistic,  because education equals economic opportunity.  People without opportunity create situations  to put focus on them,  sometimes in drastic ways.

The current state education direction diverts boys from school from 7th grade and on.  That some boys will become angry, hopeless,  lost,  and murderous should not surprise anyone,  especially the feminist driven public education corps.