A Japanese man pleaded guilty Wednesday to murdering, dismembering and storing the bodies of nine people in his apartment near Tokyo in a 2017 case involving victims who had expressed suicidal thoughts on Twitter.

In the first court hearing of his trial, Takahiro Shiraishi, the 29-year-old defendant, told the Tachikawa branch of the Tokyo District Court that the allegations against him were "correct."

His defense team, however, taking a different stance from Shiraishi, argued that he killed the victims -- eight women and one man aged 15 to 26 -- with their consent as they had expressed suicidal thoughts on social media, and therefore was guilty of the lesser charge of homicide with consent.

People form a line outside the Tachikawa branch of the Tokyo District Court on Sept. 30, 2020, for the first trial hearing of Takahiro Shiraishi, who has been indicted on charges of murdering, dismembering and storing the bodies of eight women and a man in his apartment in Zama in Kanagawa Prefecture in 2017. (Kyodo) 

Prosecutors said that Shiraishi committed "despicable and brutal murders to satisfy his desires" without the victims' consent as he raped the women and killed them all to steal their money.

His defense team argued Shiraishi was possibly either mentally incompetent or was in a state of diminished capacity at the time and should not be held criminally liable. The prosecutors insisted he was mentally competent.

According to the indictment, Shiraishi strangled and dismembered his victims from Tokyo and four other prefectures from August to October in 2017. Their bodies were discovered inside containers such as cooling boxes in his apartment in Zama, Kanagawa Prefecture.

Shiraishi is alleged to have stolen cash from them and sexually assaulted all the female victims. He owed one of the women around 360,000 yen ($3,410).

After five months of psychiatric tests, prosecutors concluded Shiraishi can be held criminally liable and indicted him in September 2018.

Flowers and drinks are seen on Nov. 20, 2017 on a street near the apartment complex in Zama, near Tokyo, where nine dismembered bodies were found in late October at the home of suspect Takahiro Shiraishi. (Kyodo) 

In the trial under the lay judge system, the victims' names were not disclosed and they were instead referred to by the letters A through I to protect their dignity.

The court has separated the victims into three groups in chronological order for a total of 24 hearings, which are scheduled to be held over 77 days. The ruling is set to be handed down on Dec. 15.

The serial killings first came to light in October 2017 when police officers visited Shiraishi's apartment and found several cooling boxes containing body parts during their search for a 23-year-old missing Tokyo woman, who later turned out to be one of the victims.

Shiraishi is believed to have approached people who expressed suicidal thoughts on Twitter under his account name loosely translated as "Hangman" and invited them to his home, saying he would help them die, according to investigative sources.

He apparently searched on the internet for how to mutilate bodies and purchased tools such as a chopper and a saw, while practicing how to tie rope knots, the sources said.

The case shocked many in Japanese society and prompted the government and social networking service businesses to increase support for young people in need of help.

Following the incident, Twitter Japan started allowing users to be linked to a nonprofit organization on suicide prevention work whenever words related to suicide are searched for.

Related coverage:

Killer of 9 used counseling techniques to lure suicidal people: expert

Social media companies to ban suicide solicitation

Japan to bolster oversight of suicidal SNS posts after serial murder

Emergency service in Japan: 119

If you are having suicidal thoughts, help is available.

For Japan, call Yorisoi Hotline at 0120279338 (toll-free). Press 2 after the recorded message for consultation in English, Chinese, Korean, Tagalog, Portuguese, Spanish, Thai, Vietnamese, Nepali, or Indonesian. The service in these languages is also available on Facebook messenger.

For those outside Japan, you can find a list of other resources here