Investigators increasingly believe the man who confessed to killing 77 people in last month's attacks in Norway planned and committed them on his own, a prosecutor said Wednesday.
Anders Behring Breivik detonated a bomb outside government buildings in Oslo on July 22, killing eight people, followed by a massacre at a youth camp on an island outside the capital where he shot dead 69 others.
There was initial speculation that others were involved in the attack, but prosecutor Christian Hatlo said that after 40 hours of questioning police are fairly certain Breivik acted alone and that he appears to be telling the truth.
Hatlo said police have been able to verify much of what Breivik told them about the attacks, and that they had not discovered "any direct lie, yet."
"That is also why we, with a certain confidence, can say that he was alone, but I have to emphasize that we have not concluded yet," Hatlo told The Associated Press.
Last week, the investigators also said they believed Breivik acted alone, but they searched his computer and cell phone records for any signs of contact with other right-wing extremists who may have helped or influenced him. Law enforcement agencies in other countries also have assisted Norway, including in the U.S., where authorities interviewed Breivik's sister in Los Angeles.
Hatlo said that all the information they received from abroad also pointed to the 32-year-old having acted alone.
"Nothing supports suspicion about other cells (being involved), rather the opposite," Hatlo said. He declined to give details.
Breivik said, in a 1,500-page manifesto posted online, that the attacks were an attempt at cultural revolution, aimed at purging Europe of Muslims and punishing politicians that have embraced multiculturalism. He told police he was part of an anti-Muslim militant network and that there are two other cells in Norway and several abroad, but that they were not involved in the attack.
Asbjoern Rachlew, special adviser to police interrogating Breivik, described him as polite and cooperative.
He said the investigators are still gathering information and allowing Breivik to do the talking. "Nobody knows more about this matter than he, and the fewer questions we ask the better at this stage," Rachlew said.
Rachlew described Breivik's answers as "detailed" and said that he seems to understand the situation. "He knows where he is and the tasks we have," he said.
Breivik, who has admitted to the facts of the case, denies criminal guilt because he believes the massacre was necessary to save Norway and Europe, his defense attorney Geir Lippestad has said.
"This whole case has indicated that he's insane," Lippestad told reporters days after the attacks.
But legal and forensic experts have said it's unlikely the right-wing extremist will be declared legally insane because he appears to have been in control of his actions and the attacks were so carefully planned.
If he is declared insane, a judge could order him institutionalized in a psychiatric ward only so long as he is deemed mentally ill, though Norway does have provisions for keeping dangerous, but no longer insane, people in custody after they're discharged from the hospital.
If convicted of terrorism charges, Breivik would face up to 21 years in prison. An alternative custody arrangement, if he was still considered a danger to the general public, could keep him behind bars indefinitely.