Jason Allison (Photo from his Facebook account)

An American assistant language teacher (ALT) at a Tokyo metropolitan high school has been arrested on suspicion of molesting a 16-year-old girl, it has been learned.

According to the Metropolitan Police Department's Harajuku Police Station, Jason Allison, 44, is suspected of molesting the second-year high school student at his Shibuya Ward apartment on June 27 after speaking to her on the street in the capital's Roppongi district. He allegedly knew she was under 18, but has denied any wrongdoing and was quoted as telling police, "I didn't know she was 16."

The victim reported the incident to police on June 29. Allison, who was arrested earlier this month, specifically stands accused of violating a metropolitan ordinance to promote the sound growth of youth.

It has also emerged that Allison had been arrested over a similar incident in April 2011 while he was working as an ALT at another metropolitan high school. According to sources close to the investigation, Kanagawa Prefectural Police arrested him for allegedly molesting a 15-year-old junior high school girl from the prefecture in violation of the same ordinance. While he was not indicted in that case, he was slapped with fresh charges and a summary indictment over a separate, similar incident and was given a fine.

Despite his police record, however, he managed to continue work as an ALT apparently because the Tokyo Metropolitan Board of Education was not aware of those past cases. According to the education board, ALTs sign employment contracts with individual schools they work for. If an ALT commits a criminal offense and is indicted, they would be dismissed and would never be hired as an ALT again.

"We were not aware of the cases six years ago and we don't know if we gave him any punishment," a representative of the metro education board's high school education guidance division told the Mainichi Shimbun. The official declined to disclose details on when Allison was hired as an ALT and his work situation on the grounds of protecting his personal information.

There are cases of Japanese teachers with a history of molestation charges being hired again at schools in different prefectures, prompting the Ministry of Education, Culture, Sports, Science and Technology in August to decide to drastically improve the database of teachers' licenses so disciplinary records can be shared across the country. Though ALT numbers are rising across Japan in preparation for English becoming a compulsory subject from the third grade of elementary school in 2020, they are not covered by the ministry's proposed system.