The motive of the assailant who carried out a knife attack on Tuesday in Kawasaki that left two dead and a dozen others injured remains unclear even after police searched his home, investigative sources said Friday.
Ryuichi Iwasaki, 51, who took his own life at the scene, had left a notebook in the house where he lived with his aunt and uncle. But its contents gave no indication about why the attack occurred, the sources said.
The suspect wrote the Chinese character sei or shou — meaning righteousness or real thing — again and again in the notebook.
“We have the impression that he wrote something nonsensical,” one of the sources said.
Iwasaki’s room, which he is said to have spent much of his time in while living like a recluse, has a TV and a game console but no internet connection, according to the sources. No computer or smartphone has been found yet.
Two magazines published more than a decade ago about serial murders that occurred overseas were also found during the search.
Based on testimony by a neighbor and analysis of security camera footage, police believe Iwasaki left his home at around 7 a.m. Tuesday.
He took an Odakyu Line train to Noborito Station, near the scene of the crime, and then walked to the place where he began attacking a group of Caritas Elementary School students and some parents waiting for a school bus at around 7:40 a.m.
Iwasaki was seen walking along the railway tracks toward the location, putting on work gloves and crouching at a nearby convenience store parking lot while carrying his bag.
Police believe it was there that Iwasaki observed the students and took out the two 30-centimeter-long knives that he used to kill Hanako Kuribayashi, an 11-year-old student, and Foreign Ministry official Satoshi Oyama, the 39-year-old father of a pupil.
Iwasaki also injured 17 others, mostly schoolchildren. He later died of a self-inflicted wound to the neck.
The police are looking at past security camera footage to see if Iwasaki had been in the area previously to scout out the location where the attack took place.
The elementary school, which closed in the wake of the attack, said Friday that it will reopen next Wednesday.