This undated photo shows Takahiro Shiraishi leaving a police station in Hachioji, suburbs of Tokyo, Japan, in November 2017. (TAKUYA INABA / KYODO NEWS VIA AP)

TOKYO - Tokyo district court on Tuesday sentenced a man to death for the 2017 murders of nine people, local media reported, ending a case that grabbed headlines in Japan with the culprit dubbed “Twitter killer” for contacting victims via the social media platform.

Takahiro Shiraishi, 30, was found guilty of murdering, dismembering and storing the bodies of the nine in his apartment in Zama city in Kanagawa, on the outskirts of Tokyo, local media reported

Takahiro Shiraishi, 30, was found guilty of murdering, dismembering and storing the bodies of the nine in his apartment in Zama city in Kanagawa, on the outskirts of Tokyo, according to reports.

In court the prosecution argued Shiraishi made contact with victims via Twitter after they expressed suicidal thoughts, the Jiji news agency reported. Using a handle which loosely translates as “hangman”, Shiraishi invited them to his apartment in Zama, promising to help them die, Jiji reported, citing the indictment.

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Shiraishi’s defense lawyers argued Shiraishi killed the victims with their approval, Kyodo reported.

Presiding Judge Naokuni Yano ruled the victims did not consent to being killed, and that Shiraishi was mentally fit to be held responsible for their murders.

Twitter Japan was not immediately available for comment.

According to the indictment, Shiraishi strangled and dismembered eight women and one man aged 15 to 26 from August to October 2017, Kyodo reported. He was also alleged to have sexually assaulted all his female victims, it added.

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Shiraishi said before the trial that even if given the death penalty he would not appeal, according to Japanese media.

In Japan, the death penalty is executed by hanging, with execution dates not made public until after the penalty is carried out.