The Zama Nine Murders

Takahiro Shiraishi used social media to contact vulnerable people and murdered nine victims in Zama, Japan, in 2017. He was convicted and executed in 2025.

A case that began online

In 2017, Takahiro Shiraishi contacted people on Twitter who had posted about suicidal thoughts. He presented himself as someone who could understand or assist them, then lured victims to his apartment in Zama, southwest of Tokyo.

The disappearance that exposed the pattern

The investigation accelerated after the brother of a missing woman used her social-media activity to trace contacts. Police searched Shiraishi’s apartment and discovered evidence connected to nine victims. Eight were women or girls and one was a man who had been looking for a missing woman.

Trial and sentence

Shiraishi admitted the killings. In 2020 he was sentenced to death after the court rejected the defense argument that the victims had consented to being killed. He did not appeal the sentence.

Execution and digital-safety questions

Japan executed Shiraishi in June 2025. The case drew international attention because social media was central to how he identified vulnerable people. It also led to renewed discussion about platform rules, suicide-prevention resources and the risks of predators targeting people who disclose a crisis online.