The only people who do things without some internal compulsion are those who are medically diagnosed as something is wrong with their brains.
A soldier killed because he was essentially ordered to kill. A jealous spouse killed because of the feeling of betrayal. The soldier killed out of duty, an internal compulsion. The jealous spouse killed because of anger, an internal compulsion. So what would compel an 18 yr old to kill elementary school children? Either this guy have something wrong with his brains, or he has psychological issues.
Maybe the reason why China did not approve your petition to entry into their country is because of poor thinking.