Japan Executes 'Twitter Killer' After 3 Years - Shocking End to Serial Murder Case That Horrified the Nation

The End of Japan's Most Notorious Social Media Serial Killer

On June 27, 2025, Japan executed Takahiro Shiraishi, infamously known as the 'Twitter killer,' marking the country's first use of capital punishment in nearly three years. The 34-year-old serial killer was hanged at the Tokyo Detention House after being convicted of murdering and dismembering nine people in 2017. This execution represents a significant moment in Japan's criminal justice system, as it was the first death sentence carried out since the formation of Prime Minister Shigeru Ishiba's government in October 2024.

Shiraishi's case shocked Japan to its core, not only because of the brutal nature of his crimes but also due to how he exploited social media platforms to target vulnerable individuals. His methodical approach to finding victims through Twitter, now known as X, highlighted the dark potential of social media manipulation and raised serious questions about online safety protocols.

The Horrific Discovery That Shocked Japan

The gruesome discovery that led to Shiraishi's arrest occurred in October 2017 when police searched his apartment in Zama, Kanagawa Prefecture, near Tokyo. What they found defied imagination - three cooler boxes and five containers holding human heads and bones stripped of flesh. The investigation began when the brother of a missing 23-year-old woman reported her disappearance after checking her Twitter messages and discovering her correspondence with Shiraishi.

The apartment, which media later described as a 'house of horrors,' contained the dismembered remains of nine victims aged between 15 and 26. The victims included eight women and one man, with the youngest being just 15 years old. The male victim was killed when he came looking for his missing girlfriend, becoming an unintended target of Shiraishi's deadly scheme. The discovery sent shockwaves through Japanese society, a nation known for its low crime rates and relative safety.

The Predator's Method: Exploiting Vulnerability on Social Media

Shiraishi's modus operandi was chillingly calculated and exploited the most vulnerable members of society. Using a Twitter username that could be interpreted as 'hangman,' he specifically targeted individuals who posted about suicidal thoughts or depression on social media platforms. His profile contained messages like 'I want to help people who are really in pain. Please contact me anytime,' creating a false sense of compassion and understanding.

Between August and October 2017, Shiraishi systematically approached his victims through Twitter, offering to help them end their lives or even promising to die alongside them. He would arrange meetings under the pretense of providing support or assistance with suicide, but his true motives were far more sinister. Once victims arrived at his apartment, he would sexually assault the women, steal money from his victims, and then murder them to cover his tracks. His first victim, a 21-year-old woman, was killed after he used her money to rent the apartment where he would later commit the remaining murders.

The Trial That Exposed a Monster's True Nature

During his trial, the full extent of Shiraishi's depravity became clear. He confessed to the murders, admitting that he killed his victims to satisfy his own sexual urges and financial greed rather than any desire to help them end their suffering. The prosecution painted a picture of a calculating predator who preyed on society's most vulnerable members for his own twisted gratification.

Shiraishi's defense team initially argued that the victims had consented to their deaths, claiming they genuinely wanted to die and had given permission for their killing. They pushed for a charge of 'consensual murder' and requested psychiatric evaluation of their client. However, Shiraishi himself contradicted his lawyers' claims, stating that he had killed the victims against their will. In December 2020, the Tokyo court rejected the defense's arguments and sentenced him to death, describing his crimes as 'extremely malicious' for targeting mentally vulnerable individuals and taking nine precious lives.

Social Media Platform Response and Policy Changes

The Shiraishi case had far-reaching implications for social media platforms, particularly Twitter. The horrific nature of how the platform was used to target vulnerable individuals led to significant policy changes. Twitter implemented new guidelines specifically prohibiting content that encourages or promotes suicide or self-harm. The platform also enhanced its reporting mechanisms and content moderation systems to better identify and remove potentially dangerous interactions.

The case sparked broader discussions about the responsibility of social media companies in protecting vulnerable users. Mental health advocates called for more robust safeguards and better resources for individuals expressing suicidal ideation online. The incident highlighted the need for platforms to balance free expression with user safety, particularly when it comes to mental health-related content.

Japan's Death Penalty System Under Scrutiny

Shiraishi's execution reignited debates about Japan's death penalty system, which operates under a veil of secrecy that human rights groups have long criticized. In Japan, death row inmates are typically not informed of their execution date until the morning it occurs, and families and legal representatives are only notified after the execution has been completed. This practice, defenders argue, prevents unnecessary psychological torture, while critics claim it violates human rights standards.

Justice Minister Keisuke Suzuki, who authorized Shiraishi's execution, defended the decision at a press conference, stating that the case was motivated by 'extremely selfish desires for sexual and financial satisfaction' and had caused 'great shock and unrest to society.' He also addressed calls for abolishing the death penalty, stating that such a move would be 'inappropriate' given public support for capital punishment in Japan. Currently, about 100 death row prisoners await execution in Japan, with nearly half seeking retrials.

The Lasting Impact on Japanese Society and Online Safety

The 'Twitter killer' case left an indelible mark on Japanese society, fundamentally changing how people view social media safety and online interactions. The case became a cautionary tale about the dangers of meeting strangers from the internet and highlighted the vulnerability of individuals struggling with mental health issues. Schools and community organizations began implementing digital literacy programs that specifically address online safety and the risks of social media predators.

The case also prompted discussions about mental health support systems in Japan, where suicide rates have historically been high and mental health resources often inadequate. Advocacy groups used Shiraishi's crimes to push for better mental health services and more accessible support for individuals experiencing suicidal ideation. The tragedy served as a stark reminder that those seeking help online may instead encounter those who would exploit their vulnerability for the most heinous purposes. As Japan moves forward, the lessons learned from this case continue to influence policies around both criminal justice and digital safety.