I’ve been waiting for Monday’s verdict in the first Khmer Rouge trial for half my journalistic career, and until last March, when the hearings at the Extraordinary Chambers in the Courts of Cambodia finally got underway, I never quite believed they were ever going to happen.

But the one thing I know about Cambodia after all these years is never to expect the expected. 

You’d think the blindingly obvious verdict would be that Kaing Guek Eav – better known as Duch – the former chief of the S21 detention centre in Phnom Penh, was found guilty and sentenced to the 40 years in prison the prosecutors have asked for.

After all his signature is scrawled on countless documents relating to S21 – now the Tuol Sleng genocide museum there are three survivors who have testified to his role there he’s even admitted personal responsibility for the deaths of more than 12,000 people who were brought to the prison.

But that would be too simple.

Not even seasoned observers are so foolish as to make predictions. 

Duch could very well be found guilty and given time off for time already spent in jail, for his apparent remorse and good behaviour.

He could be given a sentence of just a few years, or even set free for time served.

There is no doubt this trial and those that follow has allowed the Cambodian people to examine and discuss the events of 35 years ago in a way they have previously avoided, and also educate the younger generation about those horrific years for the first time.

Come the Judges’ pronouncement on Monday, whether the trial was free and fair will be hotly debated, the meaning of justice open to interpretation. 

But the three sole survivors of S-21 - Chum Mey, Bou Meng and Vann Nath - have already served a life sentence waiting for someone to be held accountable.