The suit, brought in the United States District Court in Manhattan on behalf of the families of dozens of 9/11 victims, is promising testimony from three Iranian defectors, all of them identified as former members of Iran’s central spy agency, who will implicate Iran and its terrorist proxies in Lebanon in the Sept. 11 attacks…

The court papers also include sworn statements from staff members of the 9/11 Commission, including Dietrich Snell, a former top terrorism prosecutor at the Justice Department, who says in his affidavit that “there is clear and convincing evidence the government of Iran provided material support to al Qaeda in the planning and execution of the 9/11 attack.” He said the support came in the form of “facilitating the travel of members of the 9/11 conspiracy to and from Afghanistan and Pakistan, in which countries, in my opinion and as found by the 9/11 Commission, the plot was hatched and developed.”

Another former commission staff member, speaking to The Daily Beast on condition of anonymity since he still works for the government, said the lawsuit was “a relief for a lot [of people] who believe that the commission never properly grappled with the question of what Iran knew in advance about 9/11—the whole issue of Iran came up so late that we couldn’t grapple with it.”