Updated

A psychiatric report on Anders Behring Breivik found that the confessed gunman is insane and therefore not fit to stand trial over twin attacks that killed 77 people, Norway's VG newspaper said Tuesday.

The VG report was published shortly before Norwegian prosecutors' scheduled news conference to discuss the contents of the psychiatric evaluation.

The 240-page report, compiled by two psychiatrists, was delivered to the prosecutor's office earlier Tuesday.

"We have no doubt when it comes to our conclusions," one of the experts, Torgeir Husby, told reporters when the document was delivered.

The assessment was made after 13 interviews with Breivik, an interview with his mother and an examination of his medical history. The experts also reviewed police questioning and video from the reconstruction of the shooting rampage on Utoya island, the Dagbladet daily reported.

Breivik, 32, has confessed to carrying out the July 22 twin attacks. First, he detonated a car bomb outside the government buildings in central Oslo that house the offices of Prime Minister Jens Stoltenberg, killing eight people. Then he went on a shooting spree at a youth camp on Utoya island, killing 69 mostly young people.

But he refused to plead guilty, saying that the attacks were "atrocious but necessary" in his campaign against multiculturalism and Muslims in Europe.