Looking across the courtroom where he is on trial for crimes against humanity, the chief Khmer Rouge torturer cannot avoid seeing an artist and a mechanic who sit watching him but mostly avoid his gaze.

One short and forceful, his feet dangling just above the floor, the other melancholy and drooping a bit, they are rare survivors of Tuol Sleng prison, where at least 14,000 people were sent to their deaths three decades ago.

In the weeks ahead, the two survivors will take the stand to testify against their torturer, Kaing Guek Eav, known as Duch, who commanded the prison, and both have stories to tell about a place of horror from which almost no one emerged alive.