Five people were killed in the attack in Kongsberg in October.
The man on trial over a deadly bow and arrow attack in southern Norway has pleaded guilty to murder and attempted murder.
Five people died and four others were wounded in the small town of Kongsberg last October.
The suspect -- 38-year-old Espen Andersen Bråthen -- has admitted to carrying out the attack, according to Norwegian news agency NTB.
"I admit criminal guilt for the entire charges," he said at the start of his trial at Buskerud District Court on Wednesday.
He is further accused of causing bodily harm, threatening behaviour, refusing to obey police orders and throwing knives at officers.
The attack in Kongsberg started inside a grocery store, where the suspect allegedly started shooting at people with a bow and arrow, before attacking passers-by with knives.
Andersen Bråthen was arrested more than half an hour after he began his rampage.
Norwegian prosecutors have called for the 38-year-old Danish man to be sentenced to compulsory mental health care, saying he was in a “strongly deviating state of mind” when he carried out the rampage.
After his arrest, Andersen Bråthen was detained in a closed psychiatric ward and three forensic psychiatric experts concluded that he was probably insane at the time of the killings.
The trial is expected to last until June 22.