Photo/Illutration Kosuke Omoto leaves the Komatsugawa police station in Tokyo’s Edogawa Ward on May 11. (Hiroyuki Yamamoto)

A junior high school teacher accused of killing a 63-year-old man in Tokyo apparently attacked the victim when he returned home from shopping, spending about 10 minutes at his residence. 

Kosuke Omoto, 36, who teaches at Matsue No. 5 Junior High School in the capital’s Edogawa Ward, also changed his clothing after attacking Masafumi Yamagishi on Feb. 24, investigative sources said, citing security camera footage.

Omoto, who was arrested on May 10, is suspected of slashing Yamagishi in the face, neck and elsewhere with a knife. Yamagishi, a contract employee, died of suffocation from his own blood.

A bloodstained mask was found in Yamagishi’s home. Police believe that Omoto left it behind after the attack.

Omoto, who initially denied the allegations, has refused to speak to investigators, sources said.

Yamagishi was found lying on his back with his coat on around the entrance of his home in Edogawa Ward, which is located about 170 meters from the school.

Police believe that he was attacked around 6:30 p.m. immediately after he returned from a supermarket, about 300 meters away, sources said.

A security camera caught Yamagishi shopping at the supermarket after 6 p.m. the same day.

Omoto’s school has said that he took the afternoon of Feb. 24 off after requesting a half-day off in advance. But the suspect recorded his clock-out time for the day at 7:15 p.m.

Police suspect that Omoto had tried to pretend that he was at the school around the time of the attack.

They also suspect that Omoto entered Yamagishi’s three-story house on a different day before Feb. 24.

Shoe prints found on the third floor of the residence matched those of Omoto’s sneakers, sources said.

Police searched Matsue No. 5 Junior High School, which is run by Edogawa Ward, on May 11.

The school’s principal apologized at an explanatory meeting for students’ parents on the same day.

According to a woman in her 30s who attended the meeting, her son, a second-year student, was surprised by the news of Omoto’s arrest, saying that he was a sympathetic and pleasant teacher.

The ward’s board of education has dispatched four additional psychologists to the school to provide special counseling services for students.

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