A "serious student" murdered a three-year-old girl.

A three-year-old girl was killed in a lavatory of a supermarket in Kumamoto. While her parents were shopping, she left her parents telling them she would go to the bathroom, and had never returned. The police checked the surveillance cameras and found the suspect and arrested. The suspect was a twenty-year-old private university student. The girl's body was found by the police in a river about 600 meters away.
It is said that the student had been hanging out in the market for about three hours before he saw the girl go into the lavatory. He said he captured her, and choked her off,and put the body into his rucksack he had prepared. Why he did it is unknown.
According to the reports from the media, the student is a very good and serious man.
He entered the university wanting to help poor people. So he was majoring in welfare.
Many incomprehensible crimes happen these days. The purposes of the crimes are incomprehensive. And the criminals are "good","serious","inteligent" people. What is wrong with our society? We have to consider.