It was during breaks between marathon video game sessions in his mother's apartment in Oslo that Anders Behring Breivik drafted his complicated and chilling plan.
He would kill indiscriminately with explosives and guns, surrender to authorities if he survived, then prove himself sane in court - all to publicize a manifesto accusing Muslims of destroying European society.
By any account, the attack went exactly as he intended. A court ruled Friday that Breivik was sane when he killed 77 people, most of them teenagers, in attacks that shook Norway to its core.
"His goal was to be declared sane, so on that point he is satisfied," said Breivik's defence lawyer, Geir Lippestad.
The Oslo district court found the 33-year-old rightwing extremist guilty of terrorism and premeditated murder for the twin attacks on July 22 last year. Breivik first bombed government headquarters, killing eight people, before going on a shooting massacre on Utoya island that left 69 dead at a summer camp for young members of the governing Labour party.
Prosecutors had asked for an insanity ruling, which Breivik rejected as an attempt to deflate his radical anti-Muslim views. He smiled with apparent satisfaction when the fivejudge panel declared him sane and sentenced him to a 21-year prison sentence that can be extended for as long as he's considered dangerous to society. Legal experts say that likely means he will be locked up for life.
"He has killed 77 people, most of them youth, who were shot without mercy, face to face. The cruelty is unparalleled in Norwegian history," Judge Arne Lyng said. "This means that the defendant even after serving 21 years in prison would be a very dangerous man."
In his final words, Breivik regretted not killing more people, apologizing to other "militant nationalists" for not achieving an even higher death toll. He said he wouldn't appeal the ruling because that would "legitimize" a court he said got its mandate from a political system that supports multiculturalism.
Prosecutors also said they would not appeal, bringing the legal process for Norway's worst peacetime massacre to an end and providing closure for victims' families and survivors, who have had to endure weeks of testimony from Breivik, who described the victims as traitors for embracing immigration.
"I am very relieved and happy about the outcome," said Tore Sinding Bekkedal, who survived the Utoya shooting. "I believe he is mad, but it is political madness and not psychiatric madness. He is a pathetic and sad little person."