Japan has executed a man dubbed the “Twitter killer” who murdered and dismembered nine people he met online, in the nation’s first enactment of the death penalty since 2022.

Takahiro Shiraishi was sentenced to death for murdering and dismembering nine people he met on the social media platform, now called X, in 2017. He was hanged on Friday.

Shiraishi is said to have lured his mostly female victims, aged between 15 and 26, to his apartment near Tokyo, where he killed them and cut up their bodies.

He admitted murdering all nine, having made contact with suicidal victims on Twitter and offering to help them die, before stashing bits of bodies in coolers around his small apartment, according to media reports.

Justice minister Keisuke Suzuki said Shiraishi’s crimes included “robbery, rape, murder … destruction of a corpse and abandonment of a corpse”.

“Nine victims were beaten and strangled, killed, robbed, and then mutilated with parts of their bodies concealed in boxes, and parts discarded in a garbage dump,” Suzuki told reporters in Tokyo on Friday.

“After much careful consideration, I ordered the execution,” he said.

Japan and the United States are the only two members of the Group of Seven industrialised economies to retain the death penalty.

There is overwhelming public support for the practice, and a 2024 Japanese government survey of 1,800 respondents showed 83% saw the death penalty as “unavoidable”.

In 2022, Tomohiro Kato was hanged for an attack in 2008 in which he rammed a rented two-tonne truck into a crowd in Tokyo’s Akihabara district, before getting out and going on a stabbing spree, in an attack that killed seven people.

As of December 2023, 107 prisoners were waiting for their death sentences to be carried out, the Justice Ministry told the AFP news agency. It is always done by hanging.

The law stipulates that executions must be carried out within six months of a final verdict after appeals are exhausted.

In reality, however, most inmates are left on tenterhooks in solitary confinement for years – and sometimes decades – causing severe consequences for their mental health.

There is widespread criticism of the system and the government’s lack of transparency over the practice. Inmates are often informed of their impending death at the last minute, typically in the early morning before it happens.

The high-profile executions of the Shoko Asahara and 12 former members of the Aum Shinrikyo doomsday cult took place in 2018. Aum Shinrikyo orchestrated the 1995 sarin gas attacks on Tokyo’s subway system, killing 14 people and making thousands more ill.