We actually heard this story three years ago, although it took a Google search to refresh my memory about it, but the New York Post gives us a new twist on the tale. We knew that Mohammad Atta had cased Boston’s Logan Airport in May 2001, and that security officials failed to intervene and follow up. Discovery documents from a settlement involving one of the families of a victim show that three Logan Airport employees caught Mohammed Atta in the act of casing the security posts, and all warned security officials about the potential threat. And, as we already knew, no one followed up even with multiple warnings:

At least three eyewitnesses spotted al Qaeda hijackers casing the security checkpoints at Boston’s Logan Airport months before the 9/11 attacks. They saw something and said something — but were ignored, newly unveiled court papers reveal.

One of the witnesses, an American Airlines official, actually confronted hijacking ringleader Mohamed Atta after watching him videotape and test a security checkpoint in May 2001 — four months before he boarded the American Airlines flight that crashed into the World Trade Center.

The witness alerted security, but authorities never questioned the belligerent Egyptian national or flagged him as a threat.

“I’m convinced that had action been taken after the sighting of Atta, the 9/11 attacks, at least at Logan, could have been deterred,” said Brian Sullivan, a former FAA special agent who at the time warned of holes in security at the airport.

One of the agents, Stephen Wallace, confronted Atta and his partner in May 2001 at Logan in one of these surveillance expeditions. One of the two men called him a name in Arabic, which Wallace knew because he sometimes swore in Arabic himself. Wallace then alerted “several authorities,” according to the New York Post’s account, and said, “These two clowns are up to something.”

It’s not as if no one knew that al-Qaeda was plotting against American transportation, either. The 9/11 Commission report noted that airlines had been alerted to watch for suspicious attempts to videotape or photograph security processes at airports, and the Post also notes that. Despite multiple alerts about Atta’s attempts made to do exactly what the intel warned about, no one followed up.

What’s more disturbing is that we are only finding out about this now, more than thirteen years later. The only reason we did get this information is that the attorneys representing the family of one victim in a negligent-death lawsuit decided to finally release the documents they received during the discovery process. The question will be whether the 9/11 Commission had access to them, too  — and if so, why they sat on the information. If they didn’t get this information … why not? And what else was kept from them, and/or us over the last thirteen years?