#The 18-year-old boy's grandmother is Korean accordin to Shukan Bumshun
dailymail 11:32 GMT, 27 February 2015
Japanese police on Friday arrested three teenagers on suspicion of killing a 13-year-old schoolboy, in a chilling murder some local media suggested was inspired by Isis executions such as those by Jihadi John.
The brutalised and naked body of Ryota Uemura was found in undergrowth near a river last Friday. His neck had been repeatedly hacked at, apparently with a knife, discovered nearby soaked in blood.
Low-crime Japan has been captivated by the killing, with media reporting every twist and turn in the investigation, including details of how the youngster's mobile phone was used to send a friend request on a messaging app around the time of his death.
Populist weekly Shukan Shincho reported the wounds appeared to indicate that whoever killed Ryota may have been trying to decapitate him
While a police spokesman declined to confirm the reports, investigators also obtained arrest warrants for two other teenagers over the murder in Kawasaki, an industrial city southwest of Tokyo, media said.
Junior high school student Ryota reportedly knew the suspects, and had been attacked by them previously, media said.
Violent crime is exceedingly rare in Japan and becomes very big news when it occurs.
All 3 suspects admit involvement in assault on murdered Kawasaki boy
KAWASAKI -- Three teenage suspects in the murder of a 13-year-old boy here along the Tama River have admitted that all of them were involved in the assault of the victim, investigative sources said.
Kanagawa Prefectural Police are cautiously investigating the division of roles between the three -- an 18-year-old and two 17-year-olds -- in the assault, which eventually led to the murder of the victim Ryota Uemura. The names of the three suspects are being withheld under the Juvenile Act.
The 18-year-old was quoted by the sources as telling investigators, "Three of us assaulted Uemura. I killed him."
One of the 17-year-olds, who had initially said, "I ended up being embroiled in the incident," later told investigators that the 18-year-old "told me to attack the victim, and I assaulted him."
The other 17-year-old subsequently acknowledged that he was involved in the assault of Uemura. At the same time, that suspect was quoted as also saying, "I spotted the 18-year-old holding a knife near where Uemura collapsed and was bleeding. I tried to stop the 18-year-old, but he threatened me with the knife saying, "I'll kill you.'" The boy also reportedly said he was at a convenience store before the assault of Uemura.
Prefectural police are carefully investigating the extent to which the three were involved in the assault.According to the sources, the murder scene is more than 500 meters away from the nearest convenience store. Noting that it takes a considerable amount of time to travel back and forth between the scene and the store and that some bruises have been found on Uemura's body, the sources said investigators believe that he had been assaulted over an extended period.
The prefectural police's investigation task force apparently believes that a box-cutter was the only weapon used to murder Uemura.
The body of Uemura was discovered with multiple stab wounds on the bank of the Tama River in Kawasaki Ward on Feb. 20.
March 05, 2015(Mainichi Japan)
Teen admits he killed Kawasaki boy, alleges involvement of two others
March 02, 2015 THE ASAHI SHIMBUN
KAWASAKI--The eldest of three teenagers arrested on suspicion of stabbing a 13-year-old boy to death on the banks of the Tamagawa river here last month has started admitting his involvement in the crime, investigative sources said.
The 18-year-old unemployed male, deemed as the main culprit in the killing, also told police that the other two male youths participated in the murder of Ryota Uemura, a junior high school first-grader, who was killed in this city's Kawasaki Ward early on Feb. 20.
Investigators said that the 18-year-old, who initially denied the allegation, told police that he and two other suspects, both 17, assaulted Uemura on the day with a paper-cutter knife.
The two younger teens have denied their involvement, saying that the 18-year-old killed Uemura on his own. Police are carefully investigating the trio's statements because they contradict one another. The 18-year-old is believed to be a leader of a group that the dead boy spent time with outside his school.
According to investigative sources, the 18-year-old told interrogators that he and the two 17-year-olds went to the riverbank with Uemura early on Feb. 20.
One of the 17-year-olds, who is unemployed, left the site after the 18-year-old ordered him to leave for a while. Then the lead suspect stripped off Uemura’s clothes and threw him in the river.
When Uemura crawled out from the water, the 18-year-old allegedly stabbed the boy with a paper-cutter knife that belonged to one of the 17-year-olds, a self-proclaimed manual worker, who remained at the site.
“The 17-year-old worker also stabbed Uemura with the knife,” the 18-year-old alleged in a statement to police.
The 17-year-old unemployed youth later returned to the site and tried to stop the other two, but he also joined in the assault when the 18-year-old instructed him to do so, the lead suspect said.
The 18-year-old told interrogators that the 17-year-old unemployed youth did not spontaneously participate in the crime, but did so after he ordered him to, police said.