[JURIST] US Senate Judiciary Chairman Sen. Arlen Specter [official website] said Wednesday that the US Defense Department was blocking an investigation by the Senate Judiciary Committee [official website] into a highly-classified Army intelligence program that allegedly identified four of the September 11 hijackers a year prior to the attacks. The Pentagon Tuesday ordered officers and analysts involved with "Able Danger" [Wikipedia backgrounder; JURIST report] not to testify [JURIST report] at a public hearing held by the Judiciary Committee Wednesday. An attorney representing two of those barred from testifying by the Pentagon testified before the Committee [testimony transcript] in their place. Specter said the Pentagon's actions appeared to be obstruction, citing the Department's failure to deliver documents on Able Danger until the night before the hearing. The Committee has full transcripts of all the witnesses' testimony.

Investigations into the clandestine intelligence program that used high-power computers to scan public records to find intelligence information are also being conducted by the House Armed Services Committee and the Senate Select Committee on Intelligence. Lt. Col. Anthony Shaffer, a Defense Intelligence Agency liaison to the program, has claimed that it identified Sept. 11 ringleader Mohamed Atta [Wikipedia profile] and three other hijackers as potential members of al Qaeda, but that intelligence agencies failed to act on the information. The September 11 Commission [official website] has said, however, that it did not find any evidence to verify the claims. US Secretary of Defense Donald Rumsfeld has insisted that the Able Danger program is classified and information about it cannot be publicly disclosed. Reuters has more.