Takahiro Shiraishi, under arrest on suspicion of dumping a corpse, has told police that four of the nine people he says he has killed since August were teenage girls, an investigative source has told the Mainichi Shimbun.
"There were women in their 20s (among the victims), but there were four girls in their teens, too," Shiraishi was quoted as telling police. The 27-year-old apparently also stated, "I murdered a man and a woman, a couple, right after I moved into my apartment in late August."
Shiraishi was arrested on Oct. 31 in connection with the discovery of the body parts of nine people -- eight female and one male -- in his one-room Zama, Kanagawa Prefecture apartment the day before. Police are moving to identify the remains, ascertain Shiraishi's motives and how he killed his victims.
According to a source close to the investigation, Shiraishi moved into the apartment on Aug. 22, around the same time as he was getting to know a woman on Twitter. He lured the woman to his apartment with the intent to kill her, but abandoned the plan when her boyfriend also came along, and went out drinking with the couple that night. Several days later Shiraishi asked the woman over alone and murdered her. He apparently killed the man in the apartment when he came looking for his missing girlfriend.
"I killed him because I was afraid I would be a suspect if he reported the woman missing to the police," Shiraishi was quoted as telling investigators.
Police have already determined that Shiraishi used Twitter to find suicidal people, and invited them to his apartment on pretexts including helping them take their own lives. The suspect apparently had a number of Twitter accounts under different names, and the source said Shiraishi had told investigators he "killed some people without knowing their names" because the victims, too, had been using aliases on the social networking service. Furthermore, except for the first couple, "I killed everyone the day I met them," he was quoted as saying.
According to investigative sources, there are signs that, after each killing, Shiraishi deleted the account he had used to communicate with the victim in an apparent bid to destroy evidence.
Sources have also revealed that Shiraishi reportedly began to show signs of psychological instability around two months before moving into his apartment, and had made comments to those around him including, "I want to die" and "There's no reason to keep on living." He apparently even attempted to leap to his death.