He is scheduled to stand trial next month.
The suspect, Espen Andersen Brathen, has confessed to the killings.
The five victims were fatally stabbed. He faces 11 counts of attempted murder for allegedly shooting at people with a bow and arrow in Kongsberg, a former mining town of 26,000 people.
The October 13 attacks started inside a grocery store.
Andersen Brathen, 38, is also accused of causing bodily harm, threatening behaviour, refusing to obey police orders and throwing knives at officers.
He was arrested more than half-an-hour after he allegedly started firing arrows inside the store and attacking people inside their homes.
Norwegian prosecutors want Andersen Brathen sentenced to compulsory mental health care, saying he was in a "strongly deviating state of mind" when he committed the acts, according to charging documents obtained by The Associated Press.
After his arrest, Andersen Brathen was admitted to a closed psychiatric ward.
Three forensic psychiatric experts who assessed him concluded he had a strongly deviant state of mind and was probably insane at the time of the killings.
The trial is scheduled to start on May 18 at the Buskerud District Court and expected to last a month.
