Cambodia's UN-backed genocide tribunal on Monday resumed the long-awaited trial of the Khmer Rouge's former chief torturer, more than three decades after the ultra-Communist regime was toppled from power.
Kaing Guek Eav, known by his revolutionary name Duch, faces charges of crimes against humanity, premeditated murder, torture and breaches of the Geneva Conventions, allegedly committed while he was chairman of the Tuol Sleng torture facility.
He arrived in the Phnom Penh court just after 10 am (0300 GMT).
Presiding judge Nil Nonn asked Duch a series of brief questions to verify his identity.
The judge then ordered the court's registrar to read out the findings of the pre-trial investigation that led to the indictment.
Duch, wearing a white shirt and grey trousers, sat quietly in the dock during the reading, occasionally taking notes.
The 66-year-old former mathematics teacher and born-again Christian is one of five former Khmer Rouge leader facing trial for their roles in the deaths of up to 2 million people - or a quarter of Cambodia's population at the time - through execution, overwork or starvation during the group's 1975-79 reign.
He has previously admitted guilt for crimes committed at the prison, where at least 12,000 men, women and children were tortured and sent to be murdered at the Cheung Ek "Killing Fields".
The first stage of the trial began in February and the current hearing has been scheduled to run for at least the next 40 days.
Tuol Sleng survivors, witnesses and experts will be called to testify during the hearing.
Duch faces a maximum sentence of life in prison.