Lost under the horrid Katrina radar, the Pentagon yesterday gave an important Able Danger briefing. Bottom line: five Able Danger participants have now come forward with recollections that Mohamed Atta was identified as a likely al Qaeda operative long before the 9/11 attacks. The Defense Department has still found no documentary corroboration, including the chart that Able Danger witnesses have said included the name and photo of Atta. But the briefing contained this very interesting exchange – which calls into question all of those, including the 9/11 Commission staff, who rejected Able Danger witnesses out of hand because they did not have documents to corroborate their version of events (italics is mine):

Pentagon: … What we know is that we didn’t discover such a chart when we first responded to the Commission back in November and December of ‘03 and we haven’t discovered such a chart in the current search. That’s the facts. It’s just not productive for us to get into speculating beyond what we actually know.
Media: Does that mean that because it was a classified operation a lot of documents including the chart could have been destroyed and that’s why you can’t find it?
Pentagon: There are regulations. At the time how they were interpreted, very strictly pre-9/11, for destruction of information which is embedded, I guess is the way I would say it, that would contain any information on U.S. persons. In a major data mining effort like this you’re reaching out to a lot of open sources and within that there could be a lot of information on U.S. persons. We’re not allowed to collect that type of information. So there are strict regulations about collection, dissemination, destruction procedures for this type of information. And we know that that did happen in the case of Able Danger documentation.
Media: So it’s possible then that this is how the chart cannot be found. Along with other documents, they could have been destroyed and that’s why you can’t corroborate what these people are saying or say it’s wrong.
Pentagon: Correct.

The Pentagon spokesmen went on to say that they had not to date discovered any explicit legal instructions had been given to destroy Able Danger work product. Of course, if procedures are sufficiently well known, it would not be necessary to get legal instructions to follow them.

The Senate Judiciary Committee, in the interim, has scheduled a hearing on Able Danger for September 14.