The Obama administration, meanwhile, was still debating whether to release gruesome images of bin Laden's corpse, balancing efforts to demonstrate to the world that he was dead against the risk that the images could provoke further anti-U.S. sentiment. But CIA Director Leon Panetta said a photograph would be released.
"I don't think there was any question that ultimately a photograph would be presented to the public," Panetta said in an interview with "NBC Nightly News."
After killing the world's most wanted terrorist, the SEAL team in just minutes quickly swept bin Laden's compound for useful intelligence, making off with a cache of computer equipment and documents. The CIA was hurriedly setting up a task force to review the material from the highest level of al-Qaida's leadership.
The documents provide a rare opportunity for U.S. intelligence. When a mid-level terrorist is captured, his bosses know exactly what information might be compromised and can change plans. When the boss is taken, everything might be compromised but nobody knows for sure.
Panetta, the CIA director, said bin Laden didn't have time to speak to the SEALs who killed him.
"I don't think he had a lot of time to say anything," Panetta said in an interview with PBS NewsHour. "It was a firefight going up that compound. ... I think it - this was all split-second action on the part of the SEALs."
Panetta said that bin Laden made "some threatening moves that were made that clearly represented a clear threat to our guys. And that's the reason they fired."
The question of how to present bin Laden's death to the world is a difficult balancing act for the White House. President Barack Obama told Americans that justice had been done, but the White House also assured the world that bin Laden's body was treated respectfully and sent to rest in a somber ceremony at sea.
Panetta underscored on Tuesday that Obama had given permission to kill the terror leader: "The authority here was to kill bin Laden," he said. "And obviously, under the rules of engagement, if he had in fact thrown up his hands, surrendered and didn't appear to be representing any kind of threat, then they were to capture him. But they had full authority to kill him."
For the long-term legacy of the most successful counterterrorism operation in U.S. history, the fact that bin Laden was unarmed is unlikely to matter much to the Americans he declared war against. President George W. Bush famously said he wanted bin Laden "dead or alive," and the CIA's top counterterrorism official once promised to bring bin Laden's head back on a stake.
Yet just 24 hours before the White House acknowledged that bin Laden had been unarmed, Obama's chief counterterrorism adviser, John Brennan, said: "If we had the opportunity to take bin Laden alive, if he didn't present any threat, the individuals involved were able and prepared to do that."
Will it matter around the world? Some may try to make much of it in Pakistan and elsewhere.
"This country has gone through a lot of trauma in terms of violence, and whether or not he was armed is not going to make a difference to people who were happy to see the back of him," said Mosharraf Zaidi, a political analyst and columnist in Pakistan. "The majority have a mistrust of America and this will reinforce their mistrust of America."
Others may not even believe it.
"I think he was definitely armed and he was firing on U.S. commandos," said Hamid Mir, an anchor for Geo Television. "Osama told me many times that he will not surrender; he claimed that he will fight and I think he was fighting."
In Washington, the issue will become part of the political debate over Obama's terror policies. His national security team had offered differing accounts of what would happen if the U.S. ever had a chance to kill or capture bin Laden. And Republicans have criticized the president for shutting down the CIA's controversial network of overseas prisons and trying to close Guantanamo Bay, moves they say have left the U.S. with few options for interrogating terrorists.
On Monday, the White House said bin Laden was involved in a firefight, which is why the SEALs killed rather than captured him. On Tuesday, however, White House press secretary Jay Carney said bin Laden did not fire on the SEALs. He said bin Laden resisted but offered no specifics. Bin Laden's wife rushed the SEALs when they stormed the room, Carney said, and was shot in the calf "Bin Laden was then shot and killed," Carney said. "He was not armed."
That was one of many official details that have changed in the two days since bin Laden was killed. The White House misidentified which of bin Laden's sons was killed - it was Hamza, not Khalid. Officials incorrectly said bin Laden's wife died in gunfire while serving as his human shield. That was actually bin Laden's aide's wife, and she was just caught in cross fire, the White House said Tuesday.
Carney attributed those discrepancies to the fog of war, saying the information was coming in bit by bit and was still being reviewed.
"We provided a great deal of information with great haste in order to inform you, and through you the American public, about the operation and how it transpired and the events that took place there in Pakistan," Carney told reporters Tuesday. "And obviously some of the information came in piece by piece and is being reviewed and updated and elaborated on."
Five people were killed in the raid, officials said: Bin Laden; his son; his most trusted courier, Abu Ahmed al-Kuwaiti, and al-Kuwaiti's wife and brother.
Al-Kuwaiti inadvertently led intelligence officials to bin Laden when he used a telephone last year to talk with someone the U.S. had wiretapped. The CIA then tracked al-Kuwaiti back to the walled compound in a town near Islamabad.
The home was bigger than those nearby, and there were no phone lines or Internet cables running to it. But other than that, it didn't stand out in the neighborhood, where residents tend to be very religious and jealous of their privacy. The walls are mold-stained, there are trees in the garden and the windows are hidden. Once, when a woman involved in a polio vaccine drive turned up at the driveway, the men at the gate took the vaccine, apparently to administer to the 23 children at the compound, and told her to go away.
The Pakistani government has denied suggestions that its security forces knew anything about bin Laden's hideout or failed to spot suspicious signs. But in the closed-door briefing for lawmakers Tuesday, Panetta said, "Pakistan was involved or incompetent," a U.S. official said, speaking on condition of anonymity to discuss the private briefing.
Though Monday's pre-dawn raid on that compound was a major counterterrorism victory, there had been no guarantee of success. Government analysts suspected bin Laden was living there but could never prove it. Satellite surveillance provided the military with images to plan its strike but never captured a picture of bin Laden on the property.
With no assurance that bin Laden would be there, sending troops into Pakistan was a risky call. The SEALs could storm a compound and find no terrorists at all, leaving Pakistan furious about a U.S. military incursion. Or the Pakistani military, not realizing what was going on, could send its own air force to attack the SEAL team.
"What if you go down and you're in a firefight and the Pakistanis show up and start firing?" Panetta said in an interview with Time. "How do you fight your way out?"
With officials at the CIA and the White House watching on television monitors, tensions increased when one of the two Black Hawk helicopters that lowered into the compound Monday fell heavily to the ground. Officials believe that was due to higher-than-expected air temperature that interfered with the chopper's ability to hover - an aeronautical condition known as "hot and high."
Photos released by the White House show the president and national security team watching tensely as events unfolded.
The SEALs all got out of the downed helicopter and proceeded into the compound. As they swept through the property, they handcuffed those they encountered with plastic zip ties and pressed on in pursuit of their target, code-named Geronimo. Many SEAL team members carry helmet-mounted cameras, but the video beamed back to Washington did not show the fateful showdown with bin Laden, officials said.
That word came from the SEALs on the ground: "Geronimo EKIA" - enemy killed in action.
The CIA's makeshift command center erupted in applause as the SEALs helicoptered to safety.
Now, the agency's attention turns to finding the intelligence in the computer files, flash drives, DVDs and documents hauled out of the compound. All of that is in Washington and the analysis has begun. The SEALs also confiscated phone numbers from bin Laden's body, and those might provide new leads for investigators. If the intelligence provides the kind of insight about al-Qaida operations that officials hope, the U.S. could deliver follow-up strikes against al-Qaida's remaining leaders.
Associated Press writers Kimberly Dozier, Alan Fram, , Darlene Superville, Ben Feller, Erica Werner, Pauline Jelinek, Robert Burns and Matthew Lee in Washington, Chris Brummitt in Islamabad and Nahal Toosi and Zarar Khan in Abbottabad contributed to this report.