Anders Behring Breivik has been declared sane and sentenced to prison for bomb and gun attacks that killed 77 people last year.
Reading the ruling, Judge Wenche Elisabeth Arntzen handed down a sentence of "preventive detention" of at least 10 years and a maximum of 21 years. However, such sentences can be extended under Norwegian law as long as an inmate is considered dangerous.
Breivik flashed a clenched-fist salute as he appeared in an Oslo court to receive his judgement.
Lawyers for the 33-year-old right-wing extremist said before the decision that Breivik would appeal any insanity ruling but accept a prison sentence.
Yesterday it was reported that if Breivik was found mentally fit, he will remain isolated, for now, in the high-security prison where he uses three 8-square-metre cells: a bed room, an exercise room and a study.
It's all about a philosophy of humane prison treatment and rehabilitation that forms the bedrock of the Scandinavian penal system.
"I like to put it this way: He's a human being. He has human rights. This is about creating a humane prison regime," said Ellen Bjercke, a spokeswoman for Ila Prison.
Dealing with an unrepentant killer responsible for Norway's worst massacre since World War II puts the system to, perhaps, its most challenging test yet.
During his trial, Breivik, 33, coolly described how he set off a car bomb that killed eight people and injured scores in Oslo's government district on July 22 last year. Then he unleashed a shooting rampage that left 69 people dead, mostly teenagers, at the summer camp of the governing Labor Party's youth wing. The youngest victim was 14.
In testimony that was deeply disturbing to the bereaved, the self-styled anti-Muslim militant said he was acting in defence of Norway by targeting the left-wing political party he accused of betraying the country with liberal immigration policies.
AP