That is just one of the serious questions that is still being debated more than a year after the deadly attack, Four Americans, including Ambassador Christopher Stevens, were killed last September 11th.  New York Times reporter David Kirkpatrick traveled to Benghazi for a new report on the tragedy. One of Kirkpatrick's most surprising findings is that he saw no evidence of Al Qaeda involvement. While that backs up claims made by the Obama Administration, Kirkpatrick tells Anderson he is "certainly not trying to vindicate anyone."