The man who allegedly went on a stabbing rampage at a Japanese social welfare facility for the disabled on Tuesday once dreamed of becoming a schoolteacher and practiced teaching for about a month at his former primary school, sources said.

Satoshi Uematsu, who is suspected of the mass killing at the Tsukui Yamayuri-en facility in Sagamihara, Kanagawa Prefecture, played with children and was a basketball coach for a primary school team during his training period, sources said. At the time, Uematsu had a good reputation as a “cheerful and energetic young man.”

 The school said Uematsu was the homeroom teacher for a third-grade class and taught subjects like arithmetic and the Japanese language.

 A female teacher in her 40s who was in charge of training Uematsu said: “He responded “yes” when I  gave him instructions. I remember him trying to apply [the advice he was given] during classes.”

 Uematsu obtained a teaching qualification, but is said to have failed teacher employment exams. A private company hired him after he graduated from university in March 2012. He changed jobs and began working at Yamayuri-en the following December, after working there in a temporary summer job, helping to care for disabled children.

 Originally a non-regular worker, the suspect passed Yamayuri-en’s employment exam and became a regular employee in spring the following year. His written self-introduction in an issue of the facility’s internal magazine read: “I’m moved to be able to smile and work alongside such warm-hearted coworkers every day.” 

 But in June last year, Uematsu was involved in an altercation with a passerby in Hachioji, western Tokyo. A police source said Uematsu was walking with a male acquaintance near JR Hachioji Station before dawn on June 28 when he started arguing with a male passerby, which grew into a scuffle as they started grabbing at each other. The stranger was also kicked and injured by Uematsu’s acquaintance.

 Criminal papers were filed with prosecutors against Uematsu and his acquaintance on suspicion of bodily injury.

Strange behaviour directly linked to the Tuesday killings became conspicuous this year. According to the Metropolitan Police Department’s Kojimachi Police Station and the Secretariat of the House of Representatives, Uematsu visited the lower house speaker’s official residence on Feb. 14 and 15 in Chiyoda Ward, Tokyo.

On his second visit on Feb. 15, Uematsu knelt and bowed until his forehead touched the ground, begging a police officer standing guard to accept his letter, which he had tried to submit the previous day but been refused. In the letter, he wrote that he could kill hundreds of disabled people.

 The suspect also made unusual remarks at the time about the facility’s residents, such as “They should be euthanised” and “People like that should die.”

 Concerned by Uematsu’s behaviour, the facility director spoke with Uematsu on Feb. 19. When Uematsu was asked why he was saying such things, he replied: “I suddenly noticed around January or February. I’m not wrong.” He voluntarily quit the same day.