Anders Behring Breivik is due to read out a prepared statement on the second day of his trial in Oslo.
Right-wing fanatic Breivik has gone on trial over the murders of 77 people in a case that will decide whether he is evil or insane.
The 33-year-old admitted the bomb and gun attack in Norway last summer, but entered a plea of not guilty claiming the slaughter was in self-defence. He claims he targeted the government headquarters in Oslo and an island youth camp to strike against the left-leaning political forces he blames for allowing immigration in Norway.
If deemed mentally competent, Breivik would face a maximum prison sentence of 21 years or an alternate custody arrangement under which the sentence is prolonged for as long as an inmate is deemed a danger to society. If found to be insane he will be held in a secure mental hospital. Legal experts said in either case it is virtually certain he will never be released.
Breivik wants to be judged as sane and will call radical Islamists, and extremists on the right and left to give evidence to support "his perception that there is a war going on in Europe," his lawyer, Geir Lippestad, told the Oslo court.
Having entered and performed a far-right outstretched arm salute, Breivik rejected the authority of the court as it sought to assign responsibility for the attacks. "I don't recognize Norwegian courts because you get your mandate from the Norwegian political parties who support multiculturalism," Breivik said in his first comments to the court.
Eight people were killed in Breivik's bombing of Oslo's government district and 69 died in his shooting massacre at the left-leaning Labor Party's youth camp on Utoya island outside the capital. Breivik has said the attacks were necessary to protect Norway from being taken over by Muslims. "I admit to the acts, but not criminal guilt," he told the court, insisting he had acted in self-defence.
During the opening session he remained stone-faced and motionless as prosecutors read the indictment on the terror and murder charges, with descriptions of how each victim died, and when they explained how he prepared for the attacks.
But Breivik suddenly became emotional when prosecutors showed an anti-Muslim video that he had posted on YouTube before the killing spree, wiping away tears on his cheek with trembling hands.
After a lunch break, Breivik was again expressionless as he watched prosecutors present surveillance footage of the Oslo explosion. The blast ripped through the high-rise building that housed government headquarters, blowing out windows and filling surrounding streets with smoke and debris. He did not flinch as prosecutors played a three-minute recording of a young woman's frantic phone call to police from Utoya.