The last day of the trial of Anders Behring Breivik began Friday with his defence expected to call for the acquittal of the right-wing extremist who killed 77 people in Norway last July.
Breivik's main lawyer Geir Lippestad launched into his closing arguments at 9:00 am (0700 GMT) in courtroom 250 at the Oslo district court.
Even though there is no chance Breivik will be set free, Lippestad must formally make the request since Breivik has pleaded not guilty, despite having confessed to carrying out the murderous twin attacks on July 22.
Breivik has evoked the "principle of necessity", claiming his attacks were "cruel but necessary" to protect Norway against a "Muslim invasion".
Shortly before the trial day began, another defence lawyer, Vibeke Hein Baera, told AFP of the request for acquittal that Breivik "knows that this is just a formality that is far from any plausibility."
With no illusion of getting his client off, Lippestad is expected to use most of his closing argument Friday trying to prove that the 33-year-old right-wing extremist is criminally sane, and should be sent to prison, not a closed psychiatric ward as requested by the prosecution.
The last day of the trial comes exactly 11 months after Breivik's July 22 attacks.
That day, Breivik first set off a car bomb outside government buildings in Oslo, killing eight people, before travelling to Utoeya island, northwest of the capital. There, he spent more than an hour methodically shooting and killing another 69 people, mostly teenagers.
The victims, the youngest of whom had just celebrated her 14th birthday, had been attending a summer camp hosted by the governing Labour Party's youth organisation.