Japan executed a 34-year-old death row inmate known as the "Twitter Killer," who was convicted of killing nine people at his apartment south of Tokyo in 2017.

Japan executes Takahiro Shiraishi, the 'Twitter killer,' convicted of murdering nine people. The case raised concerns over social media's role in crimes.

The execution was carried out as calls grow to abolish capital punishment or increase transparency in Japan after the acquittal of the world's longest-serving death row inmate Iwao Hakamada last year.

Japan executes Takahiro Shiraishi, the 'Twitter killer,' convicted of murdering nine people. The case raised concerns over social media's role in crimes.