The effort was so extensive and costly that the CIA went to Congress in December to secure authority to reallocate tens of millions of dollars within assorted agency budgets to fund it, U.S. officials said…

U.S. officials provided new details on bin Laden’s final moments, saying the al-Qaeda leader was first spotted by U.S. forces in the doorway of his room on the compound’s third floor. Bin Laden then turned and retreated into the room before being shot twice — in the head and in the chest. U.S. commandos later found an AK-47 and a pistol in the room.

“He was retreating,” a move that was regarded as resistance, a U.S. official briefed on the operation said. “You don’t know why he’s retreating, what he’s doing when he goes back in there. Is he getting a weapon? Does he have a [suicide] vest?”