OSLO, Norway >> Confessed mass killer Anders Behring Breivik was insane when he killed 77 people in a bomb and shooting rampage in Norway, and should be sent to a psychiatric ward instead of prison, prosecutors said Tuesday.

A psychiatric evaluation ordered by an Oslo court found that the self-styled anti-Muslim resistance fighter was psychotic during the July 22 attacks, the country’s worst peacetime massacre — which means he’s not mentally fit to be sentenced to prison, prosecutors told reporters.

The report, written by two psychiatrists who spent a total of 36 hours talking to Breivik, will be reviewed by a panel of forensic psychiatrists before the court makes a ruling on whether Breivik is legally insane.

Their conclusions contrasted with earlier comments by the head of that board, who told The Associated Press in July that it was unlikely that Breivik would be declared legally insane because the attacks were so carefully planned and executed.

"The conclusions of the forensic experts is that Anders Behring Breivik was insane," prosecutor Svein Holden said, adding Breivik was in a state of psychosis during the attacks.

In their report, the experts describe a man "who finds himself in his own delusional universe, where all his thoughts and acts are governed by these delusions," Holden said. "They conclude that Anders Behring Breivik during a long period of time has developed the mental disorder of paranoid schizophrenia, which has changed him and made him into the person he is today."

In Norway, an insanity defense requires that a defendant be in a state of psychosis while committing the crime with which he or she is charged. That means the defendant has lost contact with reality to the point that he’s no longer in control of his own actions.

The 243-page report will be reviewed by a panel from the Norwegian Board of Forensic Medicine, which could ask for additional information and add its own opinions.

"That’s interesting," the head of the panel, Dr. Tarjei Rygnestad, told the AP on Tuesday when asked to comment on the report’s conclusions.

In July, Rygnestad said that a psychotic person typically struggles to perform even simple tasks like driving a car, and that the meticulous planning and skills required for Breivik’s attacks spoke against psychosis.

On Tuesday, Rygnestad told AP that his earlier comments were based on "secondary information" and that a person’s mental state can only be determined through in-depth analysis. He said he had not read the full report yet. But he maintained his assertion that psychotic people typically aren’t able to carry out complex tasks that require intricate planning.

"Usually not. Then again, unusual things also happen," he said.

Breivik has confessed to carrying out the attacks but denies criminal guilt, saying he’s a commander of a Norwegian resistance movement opposed to multiculturalism.

Investigators have found no sign of such a movement and say Breivik most likely plotted and carried out the attacks on his own.