On an island strewn with the corpses of his victims, Anders Behring Breivik ended his killing spree the moment police approached him, authorities said, handing himself over with his hands raised high above his head.
"If he had come closer or taken longer, he would have been shot," said Anders Snortheimsmoen, the head of the anti-terror unit that arrested him.
Police gave a detailed account of the arrest for the first time Wednesday, five days after the 32-year-old Norwegian unleashed his massacre on the annual summer camp of the left-wing Labor Party's youth wing.
Breivik has confessed to both the shooting that killed 68 people and a bomb explosion that killed eight at the government district hours earlier in Oslo.
The police operation started off badly. The gunman had already been shooting on the island for an hour when eight members of the anti-terror squad and two local police officers arrived on the shore of the Tyrifjorden lake northwest of Oslo, and jumped into a police boat.
But on their way to Utoya island, the engine stalled, said Haavard Gaasbakk, one of the local police officers.
Stranded on the lake, the police had to summon two private speedboats, take them over and continue toward Utoya divided in two teams of five, Gaasbakk said.
"We can see that shots are being fired on the southern tip of the island. We can see ammunition hit the water, and we hear the cracks," Gaasbakk said.
They landed the boat, and ran about 380 yards (350 meters), yelling "armed police" to draw the gunman's attention.
"We come to a forested area and the suspect stands there right in front of us with his hands high above his head," Gaasbakk said. The shooter's weapon was 16 yards (15 meters) behind him.
Still, Snortheimsmoen said the police believed he might be wearing explosives _ and he escaped being shot by a narrow margin.
"The situation was very tense, and they couldn't see _ the way he was clothed, they worried he could have had a suicide bomber vest," Snortheimsmoen told The Associated Press.
He said Breivik used a semiautomatic rifle that he appears to have modified to make it into an automatic rifle.
Gaasbakk said some members of the team detained the suspect, while the others started administering first aid to the wounded. More police arrived. Then came the doctors and volunteers from the area who used their private boats to ferry youth to the mainland.
"There was a flood of evacuated people who came running or were carried by police," he said.
"I'm proud and humbled by the crews that were there and contributed," Gaasbakk said. "They showed determination and courage the whole way."
Breivik's lawyer said Tuesday his client had expected police to detain him sooner.
Nordstrom contributed from Stockholm.