The killer shot his papa firstly. And His mother worked at here. So next he went to school and killed her. Then. All lost control. Eyewitness heard over hundreds of shooting. Why happened it. 

According to investigation. 

The killer is sole. No one is his companion. He fancied at Japanese culture. His parent are strictly to him. Very tight. So he couldn't make any friend. Like a wolf. To be alone. Parent are good at collecting guns. Also teacher of this school. The boy is good student. But preferred to be alone. Then. American law allow civilian to buy Guns by ID card. Or green card. But government took ineffective charge of using gun. Lead to gun abuse. Frequently have had gun shooting in school and public place. Many innocent man turned to victim. Bipartisan is regardless of this. Cuz it is kind of traditional culture. On constitution. People are allow to have gun legally. To keep Individual safe and unrestrained. So problem came out.  What is your view as America occurred this case. In china    An insane man also killed 22 students. Officer had negative acts. Report are fews. Compared with America shooting. Why it is unfair. And why children are target for always.