In the White House Situation Room, President Obama and his national security team watch a live feed during the raid on Osama bin Laden’s compound. Official White House photo by Pete Souza

“Thank you so much!” a tearful Maureen Santora said, embracing the ex-CIA operative who had helped avenge the murder of her son and nearly 3,000 other victims of Osama bin Laden.

Santora, the mother of Firefighter Timothy Santora, killed on 9/11 at age 23, was thanking Mark Kelton, the Pakistan station chief whose intelligence work helped enable the U.S. Navy SEALs raid on bin Laden’s Abbottabad, Pakistan, compound in 2011, and the death of the terror mastermind.

“The last thing bin Laden saw was an American soldier,” Santora recalled with comforting satisfaction.

The emotional encounter followed a press briefing at the National September 11 Memorial & Museum for “Revealed: The Hunt for Bin Laden,” an exhibition opening on Nov. 15 that traces the 10-year quest by intelligence agents, law enforcement and the military to find the elusive al-Qaeda leader and bring him to justice.

“It wasn’t like finding a needle in a haystack,” said Mary Galligan, a former FBI Special Agent who played a leading role in the agency’s terror investigations. “It was looking for a needle in a haystack-size of needles.” The story is told, in many cases for the first time, through the eyes of the principals involved in the hunt and the raid, and through newly declassified documents and artifacts.

Kelton and Galligan appeared at the press conference to offer first-hand knowledge about what the museum calls “the greatest manhunt in American history.”

“I had the opportunity and the honor to tell people who were working in a very difficult environment that we had delivered justice to a murderer, and it was a very proud moment,” said Kelton, who had watched the assault and brought the news to his co-workers, many of whom were given no prior knowledge of the raid. “And it still brings emotion.”

In 2010, Kelton had been assigned by then CIA Director Leon Panetta to uncover who was in the Abbottabad compound. There were no electronic signals to monitor, even the trash was burned behind the 12- to 18-foot-high walls, he said. “Over time we developed a way to get close to the compound and obtained information that gave us tremendous confidence, at least to me, that the people inside fit the profile of the bin Laden family and the couriers’ families.”

He continued: “After a while when you’re in operations you get a feeling and that had the feeling. When they asked me, I said, ‘Yeah, I’m over 90 percent certain. And what do we do? We have to go after him. You can’t leave Hitler in his bunker.”

The exhibition, three years in the making, covers both the pursuit of bin Laden and the parallel efforts of the al-Qaeda network to hide him. The show’s message, said its curator, Clifford Chanin, is “first and foremost the extraordinary commitment of the people who were on this 10-year hunt after 9/11,” a commitment, he added, made by “thousands and thousands of people.”

Mountains of material had been gathered during the bin Laden search, potential documents and artifacts that would help tell the story. But obtaining the once sensitive material from government agencies was slow going, Chanin said.

“We never quite knew what we would be able to get. Who we would have access to. What materials would be made available to us because most of this stuff had been classified or hadn’t been cleared for public release and couldn’t even be described to us as we went to the various agencies and said, ‘Well, we’re looking for the kind of thing that would make this point.’”

Intelligence materials, objects taken during raids or used by the SEALs, a binder with bomb-making instructions, a passport used by al-Qaeda members. These are a few of the more than 60 artifacts in the show, many never before displayed publicly. Its centerpiece is a model of the compound used to brief President Obama and plan the SEALs mission. On video, visitors will hear the story told by those who conducted the hunt, and top level officials—including Obama—who oversaw it.

“My son would be very proud that they have continued the tale,” Maureen Santora said. And speaking for many victims’ family members, she added, “This is the completion. The head of the snake is dead.