Prosecutors have sent an 18-year-old and two 17-year-old males to the Yokohama Family Court over the killing of a 13-year-old boy on a riverbank in Kawasaki, south of Tokyo, last month.
The court also decided on Thursday to keep the suspects in custody for two weeks, with plans to decide at a closed-door session later, whether to send them back to prosecutors or to a reformatory.
If the court decides they should face prosecution and sends the teens back to prosecutors, they would likely be tried as adults.
The prosecutors sent the 18-year-old to the court on suspicion of murdering Ryota Uemura, and the two 17-year-olds on suspicion of inflicting injuries causing death.
The three were arrested late last month on suspicion of fatally stabbing the junior high school student on the banks of the Tama River in Kawasaki, Kanagawa Prefecture, on Feb. 20. The prosecutors did not provide the reason for changing the allegations against the two 17-year-olds.
The names of the three suspects are being withheld because they are minors.