TOKYO: Japanese police served a 17-year-old boy with a fresh arrest warrant Saturday in connection with a knife attack in front of a University of Tokyo campus that injured three people last month.

The second-year high school student in Nagoya, Aichi Prefecture, was served the new warrant on suspicion of attempting to murder a 72-year-old man, one of the three, as well as violating the swords and firearms control law on Jan. 15.

The man was stabbed in the back and seriously injured, but his condition is now stable, according to Tokyo’s Metropolitan Police Department.

The boy was first arrested on the spot for allegedly attempting to murder the other two, both high school students who came to the campus for a unified university entrance examination.

The police found that the boy had looked up past heinous crimes using a smartphone before the attack, according to sources familiar with the investigation.

The suspect has told police investigators that he wanted to enter the University of Tokyo to become a doctor, but that he lost confidence because his academic results did not improve from about a year ago, according to the police.

Then, the boy has said he wanted to kill himself after murdering people, according to the police. “He had stuck to being a high achiever,” one of the investigators said.

“Studying might have become his only value. He had good academic performance until junior high school, but it deteriorated after entering senior high school,” said Yasumasa Kosaka, professor of adolescent psychology at Wako University.

This “led him to an extreme idea that he has no choice but to die since he won’t make it into the University of Tokyo,” Kosaka said.

JIJI Press