Tokyo police have arrested a 36-year-old junior high teacher for allegedly stabbing a male resident near the school and killing him.
The Tokyo Metropolitan Police Department arrested Omoto Kosuke on Wednesday on suspicion of killing 63-year-old Yamagishi Masafumi at his home in Edogawa Ward in February.
A passer-by notified the police after finding the victim lying in the entrance, bleeding.
Investigative sources say security cameras nearby captured images of a suspicious-looking person wearing dark clothes.
The sources say Omoto has denied involvement in the case.
The victim is believed to have been killed shortly after he returned home.
Tokyo police say the suspect may have broken into the house to carry out a theft, and encountered the victim.
The junior high school where Omoto works held a news conference after his arrest, together with members of the local board of education.
The school said he teaches special needs students.
It said the school held a regular test on the day of the incident and the teacher took a leave of absence in the afternoon.
The school plans to hold a parents' meeting on Thursday to explain the situation.
The principal of the school told reporters he was surprised when he was informed by the police on Wednesday morning.
He added that he will offer his apology should the allegations turn out to be true.
The principal said he had considered Omoto as capable of addressing his students individually, taking into account their personalities.
He said he hoped to discuss the matter with the education board, with the mental care of the students as the top priority.