Police attorney Paal-Fredrik Hjort Kraby told a news conference they will interview Anders Behring Breivik again on Friday, but did not indicate what they would ask him about.
Breivik has confessed to the attacks, saying he was trying to save the Western world from Muslim colonization and justifying the rampage in a 1,500-page anti-immigrant manifesto. His attorney has said he considers himself a "savior" and that he is likely insane. He has pleaded not guilty to the terrorism charges he faces.
Breivik claimed wide contact with individuals and groups he says support his opposition to immigration. But questions persist about whether there was a genuine network or if Breivik's statements were exaggerations.
Police have so far only intervewed the suspect once, in a seven-hour session the day after the attack. He said Breivik is in contact only with his lawyer and investigators.
Norway's response to the camp attack, on the island of Utoya, has been criticized. Though it is just 25 miles (40 kilometers) from Oslo, it took police 90 minutes to get there. The crew of the sole helicopter available to police was on vacation, and the first boat that officials tried to take to the island broke down.
The leader of Norway's Delta Force anti-terror police unit on Wednesday defended the special operations team and said the breakdown didn't cause a significant delay. The team jumped into other boats and got to Utoya quickly, police officials said.
Police gave an eerie account of the end of the siege, saying Breivik obediently gave up the moment police approached him, holding his hands over his head.
"It was a completely normal arrest," said officer Haavard Gaasbakk.
Prime Minister Jens Stoltenberg said an independent commission will be formed to investigate the attacks and determine what lessons can be learned from the response. The commission also is to help survivors and relatives cope with the aftermath. Parliament said it is willing to help pay for funerals, and a monument will be built to commemorate the victims.
He said Norway will never be the same, but insisted the massacre shouldn't change the country's culture of tolerance, calling on Norwegians to embrace the oppenness Breivik said he was trying to destroy.
Perhaps mindful of many Norwegians' reserved ways, Stoltenberg urged the country to fully grieve: "I have cried, and I have told many people that they should not hesitate to cry."
The national sense of heartbreak is being renewed daily as police slowly release names of the dead. The identities of only 17 of those known to have been killed have been officially confirmed. Eight died in the explosion and 68 died in the camp shootings.
Georgian officials said Thursday the body of a young Georgian woman missing after the shooting rampage has been found. Tamta Liparteliani's body had been found on the bottom of the lake with gunshot wounds in the back. She was identified by her fingerprints, Georgian Deputy Foreign Minister Nino Kalandadze said.
The youngest-known victim so far was identified Wednesday - camper Sharidyn Svebakk-Boehn, who turned 14 five days before the rampage. Another victim confirmed dead at the camp was a stepbrother of Crown Princess Mette-Matrit, 51-year-old police officer Trond Berntsen, who had been providing security on the island.
An employee of Stoltenberg's office, 51-year-old Anne Lise Holter, was confirmed Wednesday as one of the eight dead in the bomb blast.
Heintz reported from Stockholm. Louise Nordstrom in Stockholm and Bjoern H. Amland in Oslo contributed to this report.