What he was about to describe, he cautioned, would be ''horrendous''. But no warning could truly prepare Oslo criminal court for the experience of listening to Anders Behring Breivik detail in a calm, blank way how he gunned down terrified teenagers in the second of two attacks he carried out on July 22 last year.
The 33-year-old spent two hours on Friday afternoon giving a bullet-by-bullet account of what he refers to as his ''operation'' on the island of Utoya, where the youth wing of Norway's Labour party was holding its annual summer camp. He shot and killed 67 people on the island that day; two others died trying to escape.
Leaning back in his chair, fiddling with a pen in his right hand, Breivik - flushed, but never losing control - told how some of the teenagers he killed were so paralysed with fear that he had time to reload his rifle before shooting them. He'd never seen such a thing, he said - not even on TV.
He recalled teenagers ''playing dead'' whom he slowly approached before shooting them at close range.
Relatives of those he had killed hugged each other. Some who had dodged his bullets stared straight ahead. There were tears in the eyes of some of the most experienced journalists in the courtroom. Lawyers bit their lips as they listened to Breivik, in a clear, measured voice, remember how he decided halfway through the massacre to ''look for places where I would naturally try to hide''.
On the west side of the island, he said, he came across a group ''hiding, pressing themselves against the cliff face''.
With nowhere to run, he was able to shoot them too. Another gang had clustered near an escarpment. Spotting them, he murdered five. Breivik remembered campers ''screaming and begging for their lives''.
One boy saw him coming and shouted ''Please, mate''. Breivik shot him regardless: ''I shot everyone there.'' He repeatedly recalled taking what he called ''follow-up'' shots to ensure that those on the ground were dead. It was part of a string of military terminology he used to describe the massacre. He also referred to using a building on the island as a ''forward operational base''. It was to there that, in one of the most tragic twists, he had persuaded his first victim to help him carry a bag containing extra rounds of ammunition.
Trond Berntsen, 51, one of the island's security officials, had met Breivik off the ferry. Utoya's head of security, Monica Elisabeth Bosei, had been told by Breivik that he needed her help to sail to the island because he was a police officer who had come to reassure campers in the wake of the Oslo bombing he had carried out barely an hour earlier. He was dressed in police uniform, and Bosei believed him. Within five minutes of Breivik setting foot on the island, both the security officials were lying dead.
But he said that he had deliberately spared those who looked the youngest, recalling at one point how he encountered ''a small boy … crying hard''. Breivik said: ''I don't know if he is paralysed, he is just standing there, crying. And he looks very small, very vulnerable, I thought he can't possibly be 16 years old, so I said 'fine, just relax, things will work out'.'' He turned around and carried on his killing spree.
''My point was … to kill 600,'' he told the courtroom. Breivik intended to shoot ''as few as possible because it was cruel,'' preferring to ''scare them into the water so they would drown,'' as he tracked his movements on the island using an aerial photograph.
Hearing a helicopter overhead, Breivik said he considered killing himself. ''I thought, 'do I really want to survive this? I will be the most hated person in Norway and every day for the rest of my life will be a nightmare'.''
What stopped him pulling the trigger was the thought of the 1801-page manifesto he had spent five years compiling in an attempt to make Norway wake up to what he sees as the ''systematic deconstruction of the Norwegian and European culture'' from multiculturalism. ''I thought 'you should let yourself be arrested and fight for your cause through the judicial procedure or prison'.''
He said he had thought about wearing a swastika on his chest as a pure fear factor, but decided against it because he didn't want people to think he was a Nazi.
Questioned by his own lawyers how he was able to carry out the attacks, he described a ''meditation'' technique he had developed. He insisted he was a ''nice person'' who was capable of empathising with those whose lives he had ruined, but he had chosen not to as a self-preservation technique.
''If you are going to be capable of executing such a bloody and horrendous operation you need to work on your mind, your psyche, for years. We have seen from military traditions you cannot send an unprepared person into war.''
Asked how he was able to talk about the atrocities in such an impassive manner, Breivik said he had learnt to rely on ''technical, de-emotionalised language''. ''People say, 'he must be a monster, he cannot be from this planet, he must have no emotions and empathy left', but this has to do with preparing and training.''
Guardian News & Media, Associated Press, Bloomberg