Japan carried out its first execution in three years after executing the man known as the "Twitter Killer" -- a chilling case that horrified the nation and sparked international outcry.

Takahiro Shiraishi, 34, was hanged on June 27, 2025, for murdering and mutilating nine people whom he contacted through Twitter, including eight young women and one male victim, as People reports.

Shiraishi’s victims, many of whom were in their teens or early 20s, had expressed suicidal thoughts online. Posing as someone willing to help them die, he initiated conversations using the social media platform then known as Twitter, now X. He lured the women to his apartment in Zama, a suburban city roughly 20 miles from Tokyo.

There, he committed a series of brutal crimes, beating, strangling, raping, robbing, and dismembering his victims. Justice Minister Keisuke Suzuki noted that the women were "mentally fragile" and that Shiraishi's crimes were driven by "sexual and financial desires." Shiraishi raped all eight of the female victims, three of whom were minors, with the youngest just 15 years old. One victim brought her boyfriend with her. Shiraishi murdered the young man as well, reportedly to avoid being caught by law enforcement. His plan failed after the brother of one female victim began investigating her disappearance on his own.

Police make grim discovery

Tracking digital communications recovered from his sister’s device, the concerned brother unearthed exchanges between Shiraishi and his sister on Twitter. He provided this information to police, which led them to conduct a search of Shiraishi’s apartment in 2017.

The scene investigators found inside was gruesome. Human remains from all nine victims were discovered, stored in coolers and containers around the apartment. In an effort to conceal the stench of decomposition, Shiraishi had used cat litter to mask the odor.

The case gripped Japanese media and the public imagination for its shocking brutality and the methodical way the killer exploited vulnerable individuals online. It also renewed debate over mental health, predator behavior on social media, and Japan’s criminal justice system.

Crimes spark national, global debate

The judicial process began in 2020, with Shiraishi making his first court appearance at the Tokyo District Court’s Tachikawa branch on September 30 that year. He did not dispute the charges and admitted to killing his victims.

Following years of appeals and legal reviews, Justice Minister Suzuki stated that the decision to proceed with execution was reached after “careful consideration.” Under Japanese law, executions are carried out by hanging, often with minimal notice to the inmate or their family.

Japan, along with the United States, remains one of the only nations among the G7 to uphold capital punishment as part of its judicial system. The country’s approach has long faced criticism from abroad, particularly within the European Union.

Europe condemns death penalty decision

In response to the execution, a spokesperson from the EU issued a statement reaffirming its opposition to the death penalty in all circumstances. The union highlighted that capital punishment undermines the right to life and creates the risk of irreversible miscarriages of justice.

“The use of the death penalty is incompatible with the inalienable right to life and the right to live free from torture or cruel, inhuman or degrading punishment,” the EU said. The bloc also criticized capital punishment's effectiveness, asserting that it "fails to act as a deterrent to crime."

Despite this criticism, the Japanese government stood by its decision. Suzuki maintained that the action taken was just and proportionate to the scale of the crimes committed.

Lessons to learn

1. Online interactions pose real risks: It's vital to remember that predators can use the anonymity of platforms like Twitter -- now X -- to exploit vulnerable individuals. Users, especially minors, should exercise caution when engaging with strangers online.

2. Recognizing mental health red flags: Many of Shiraishi’s victims had expressed suicidal thoughts, leaving them vulnerable to manipulation. This underscores the importance of access to mental health resources and of taking warning signs seriously -- for yourself and others.

3. Always report suspicious behavior: This case may have gone unsolved if not for the persistence of one victim’s brother. If a loved one disappears or is acting strangely, especially after contact with a stranger online, contacting authorities without delay can make all the difference.

However, no matter how prepared we are, crime can strike anyone. It's important to recognize that victims should never be blamed, and our responsibility as a society is to protect and support them.

Why this story matters

This case underscores the dangers that vulnerable people face both online and offline. It also prompts an urgent reassessment of how we treat mental health struggles and online safety, particularly among young people.

Moreover, it raises global ethical questions about the use of the death penalty, especially when public outrage, political pressure, and human rights concerns collide.

Ultimately, it pushes governments and communities to reexamine how legal systems, technology platforms, and social services can work together to prevent such horrors from occurring again.