YOKOHAMA – The eldest of three teenagers charged in the killing last year of a 13-year-old boy on a riverbank in Kawasaki pleaded guilty Tuesday to assault and murder.
The 19-year-old boy, whose name is being withheld due to his age, is the suspected ringleader in the February 2015 slaying of Ryota Uemura.
The case is being heard in the Yokohama District Court by three professional and six lay judges.
Two 18-year-old boys have been indicted on the lesser charge of causing injury resulting in death.
The 19-year-old man had already admitted involvement in the crime during deliberations in family court.
Expected to run from Tuesday to Thursday, the trial will likely focus on extenuating circumstances and sentencing options. It will include an opportunity for Uemura’s mother to make a statement.
According to the indictment, the 19-year-old repeatedly hit Uemura in the face during an attack lasting roughly 30 minutes early on Jan. 17 last year in Yokohama, inflicting injuries that required about two weeks for recovery.
He is alleged to have killed Uemura on Feb. 20 last year by repeatedly cutting his throat on the banks of the Tama River in neighboring Kawasaki.
Friends of Uemura reportedly confronted the 19-year-old following the initial assault and made him apologize, which Yokohama prosecutors said significantly influenced his motive to kill.
In their opening statement, the prosecutors alleged that during the earlier incident in Yokohama, the defendant beat up Uemura because the young victim was being “overly familiar . . . and this annoyed him.”
After that, Uemura’s friends turned up at the boy’s house sometime in late January.
Then, hours before he was slain Feb. 20, the 19-year-old pushed Uemura to answer whether he had told the friends about the beating and became enraged when Uemura initially denied having done so, according to the prosecutors.
They alleged that at the bank of the Tama River, the defendant sliced Uemura’s cheek several times with a box cutter and decided to kill him, fearing retaliation if the boy remained alive.
The prosecutors said the alleged ringleader pinned Uemura down on the riverbank and took turns slashing him with the other two boys before forcing him into the river, where he became unable to move.
The prosecutors said 43 knife wounds were found on Uemura’s body, including 31 to the neck.
Lawyers for the defendant said the death was accidental. They said their client had not set out to kill Uemura and was handed the box cutter by one of the other boys.
“While taking turns cutting (Uemura) with the other boys, he became unsure of what to do next and momentarily lashed out, killing him,” a counsel for the defendant said.
Investigative sources say one of the two other boys denies his involvement in the crime, while the other admits to slashing Uemura but maintains he was forced to do so by the ringleader.
The prosecutors said Uemura’s mother took her son at his word when he attributed his wounds from the initial beating to having broken up a fight between his older friends.
“I deeply regret that if only I had asked him more about it the murder might not have occurred,” she was quoted as saying.
Uemura’s father also attended the trial session, his sobs periodically audible in the courtroom as prosecutors described how his son died.