Brian Ross Investigates: Osama bin Laden

May 7, 2011 — -- With this week's historic killing of al Qaeda leader and 9/11 mastermind Osama bin Laden, a special edition of "Brian Ross Investigates" is on location at Ground Zero examining a week's worth of coverage the death of the most wanted terrorist in the world.

ABC News Chief Investigative Correspondent Brian Ross and the Investigative Team examine the daring operation that took bin Laden down, the young wife who defended him, the secretive helicopters used to pull off the mission and what Pakistan could or should have known.

"I think there's a real possibility that we'll find that there were former members of the Pakistani military and military intelligence who were sympathizers with al Qaeda and with various other terrorist groups, and that they were running their own sort of renegade support system for al Qaeda," former White House counterterrorism official Richard Clarke told Ross.

Speaking of possible retaliation for bin Laden's death, Clarke says the threat is real and al Qaeda is not dead.

"There are two periods to worry about: the next few days where there could be lone wolves who could strike out in the United States or elsewhere around the world in retaliation, and then there's another period several perhaps months from now, because it takes months to plan one of these operations," Clarke said. "I think al Qaeda if it's capable of doing a big operation will want to do one just to prove it's alive. That could take a while."

Ross is on the scene of Ground Zero as President Obama visited in a sort of victory lap, meeting with some of the families who lost loved ones on that fateful day.

He answers viewer questions through Twitter and Facebook and speaks with producer Matthew Cole from the ABC News Investigative Team, who reports from outside bin Laden's compound in Abbottabad, Pakistan.

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