Some past investigations and reports regarding intelligence failures:

President Bush's Commission on Weapons of Mass Destruction

Federal officials say the president's commission on weapons of mass destruction is expected to call for dozens of changes, including improved information sharing among spy agencies, better traditional spying and new steps to improve analysis.

Senate Intelligence Committee Report on Prewar Intelligence on Iraq

Senators concluded that the CIA kept key information from its own and other agencies' analysts, engaged in "group think" by failing to challenge the assumption that Iraq had weapons of mass destruction and allowed Bush and Secretary of State Colin Powell to make false statements.

Duelfer Iraq Weapons Investigation

Charles Duelfer, the chief U.S. arms inspector, said he found no evidence that Iraq produced weapons of mass destruction after 1991 and that Saddam Hussein's ability to develop such weapons had diminished, not grown, during a dozen years of sanctions imposed on Iraq. But Duelfer supported Bush's argument that Saddam remained a threat.

Sept. 11 Commission

America's leaders failed to grasp the gravity of terrorist threats before the Sept. 11, 2001, attacks, but the commission stopped short of saying the suicide hijackings could have been prevented. While the panel did not fault Bush or former President Clinton, it said both failed to make anti-terrorism a top priority.

Sept. 11 Commission on Aviation

A portion of the Sept. 11 Commission report said the Federal Aviation Administration received repeated warnings in the months prior to Sept. 11 about Al Qaeda and its desire to attack airlines.

Joint Inquiry Into Sept. 11 From the House and Senate Intelligence Committees

The committees' final report identified numerous blunders, oversights and miscalculations that prevented authorities from stopping the attacks.

CIA Inspector General Inquiry Into Sept. 11 Failures

The report is expected to find personal culpability for Sept. 11. The top Democrat on the House Intelligence Committee, Rep. Jane Harman, D-Calif., has called for its release.

Justice Department Inspector General Investigation

The inspector general investigated handling of intelligence information prior to Sept. 11, including the case of Zacarias Moussaoui, the only U.S. defendant indicted in connection with the attacks. The inspector general is trying to get approval to release an unclassified version.

Justice Department Inspector General Report on Prisoner Abuse

The report found that the warden and guards at an unidentified federal prison discriminated and retaliated against Muslim inmates.

Church Report Into Prisoner Abuse

Vice Adm. Albert T. Church's report said there was no single explanation for the mistreatment of Iraqi, Afghan and other prisoners under the control of U.S. military personnel.