Police suspect a 17-year-old girl who was found dead in a burned Tokyo apartment earlier this month could have been drowned, as autopsy results showed there was water in her lungs, investigative sources said Tuesday.
An 18-year-old high school student is the primary suspect in the murder of the girl, Mai Sato, the sources said. The police said they have yet to formally determine the cause of her death.
The suspect, whose name is being withheld because he is a minor, told investigators early in his interrogation that he strangled Sato, only later to change his story several times, according to sources. He has remained silent since the day after his arrest Saturday.
The search history on his smartphone suggests he may have sought information about setting fires using oil and "poisonous herbs" that can be found on the street, the sources said.
The police believe the teens, who went to the same school, were dating. A search of their Line chat history showed no signs that the two were arguing.
According to the sources, on May 4 Sato was found on her back on a burned futon in her mother's room, where authorities believe the fire started in the apartment in Taito Ward.
The boy was spotted at JR Uguisudani Station at 8 a.m. on May 4 and 15 minutes later at a convenience store where Sato worked part time, according to the sources. He called the police soon after the fire started in her apartment at 8:35 a.m.
The police believe the suspect may have assaulted Sato at her apartment or somewhere nearby between around 8:30 p.m. on May 3 and 8:35 a.m. the following day.