Causing “the most casualties in the shortest time,” Mr. Kaing Guek Eav — infamously known as Comrade Duch — holds one of the most chilling records in modern history. As the commandant of Tuol Sleng Prison, code-named S-21 (ស២១), during the Khmer Rouge’s reign from 1975 to 1979, Duch played a central role in Cambodia’s genocide, overseeing a facility that became synonymous with torture, terror, and mass murder.
Tuol Sleng was once a peaceful high school in the heart of Phnom Penh. Under Duch’s direction, it was transformed into a high-security prison and interrogation center — a place where the regime’s paranoia about internal enemies took a horrifying physical form. Between 14,000 and 17,000 men, women, and children were imprisoned at S-21, often on fabricated charges of espionage or treason. Virtually all were tortured into forced confessions and then sent to the Killing Fields of Choeung Ek for execution. Only a known 12 to 15 individuals are believed to have survived.
What set Duch apart was not just the scale of his crimes, but the methodical precision with which they were carried out. Every prisoner was photographed, documented, and interrogated — their final moments reduced to administrative records. Duch ensured every confession, no matter how coerced or absurd, was catalogued. His dedication to “order” revealed the horrifying efficiency of the Khmer Rouge’s campaign of extermination against its own people.
Following the fall of the regime in 1979, Duch disappeared. He lived under the alias Hang Pin, converted to Christianity, and worked for humanitarian organizations — all while hiding in plain sight in rural Cambodia. It wasn’t until 1999 that journalist Nic Dunlop uncovered his identity, leading to his arrest and bringing decades of impunity to an end.
In 2009, Duch became the first senior Khmer Rouge figure to face trial at the Extraordinary Chambers in the Courts of Cambodia (ECCC), a hybrid UN-backed tribunal established to bring justice for the crimes of the regime. Charged with crimes against humanity, war crimes, and grave breaches of the Geneva Conventions, he initially expressed remorse and asked for forgiveness, though he later attempted to minimize his responsibility by claiming he was merely following orders.
The court found otherwise. In 2010, Duch was convicted and sentenced to 35 years in prison, later extended to life on appeal. His trial marked a milestone — not just for Cambodia, but for the broader pursuit of international justice. It exposed the inner mechanics of a system built on fear, delusion, and absolute power — and it gave voice, at last, to survivors and families long silenced by trauma.
Duch died in 2020 at the age of 77, leaving behind a legacy of unimaginable cruelty. Today, Tuol Sleng stands as the Tuol Sleng Genocide Museum — a place of remembrance and education, preserving the memory of those who suffered and perished within its walls.
The record held by Comrade Duch as the world’s most prolific war criminal is an unwanted and tragic distinction. His story is a reminder of how ideology, when weaponized and unchecked, can lead to devastating consequences. It underscores the urgent need for historical reckoning, accountability, and the collective will to ensure such darkness never returns — in Cambodia or anywhere else.