The premier U.S. law enforcement agency, the Federal Bureau of Investigation, is expected to come under harsh scrutiny this week in hearings held by the independent commission investigating the September 11, 2001 terrorist attacks.

The FBI's response to terrorist threats before the September 11 attacks will be a major focus of this week's public hearings by the 9/11 commission.

The current and former FBI directors as well as current Attorney General John Ashcroft and former Attorney General Janet Reno will all testify and answer questions before the commission.

The spotlight is on the FBI because of the release of a previously secret intelligence memo given to President Bush about a month before the 2001 attacks.

The memo, known as a PDB or President's Daily Brief, was a summary of the domestic terror threat posed by al-Qaida in August of 2001. The memo mentions that the FBI was conducting 70 field investigations involving suspected al-Qaida cells inside the United States.

9/11 commission member Slade Gorton, a former Republican senator from Washington State, was asked about the FBI's performance prior to 9/11 on Fox News Sunday.

?It seems to me that the FBI has more questions to answer than Condoleezza Rice or Dick Clarke or anyone that we have had testify before us so far,? Mr. Gorton said.

The August intelligence memo also refers to the possibility of al-Qaida trying to hijack airliners, though there is no mention of using the planes as missiles.

The memo notes other suspicious activity, including surveillance of federal buildings in New York.

The 9/11 commission is expected to press the FBI and the CIA this week as to why the two agencies did not share more information with each other that could have exposed, at least in part, what the al-Qaida hijackers were up to before September 11.

Richard Ben-Veniste is one of five Democrats on the 9/11 commission. He also spoke on Fox News Sunday. ?The FBI and the CIA did not talk to each other. Everyone knew that,? Mr. Ben-Veniste said. ?The question was whether you could make them do that and the only way to make them do that was through leadership at the top to make sure they butted heads together, get them in the same room and then pulse [press] the agencies. What do you know? Get all of your agents out there with messages to say, tell us everything you know at this moment.?

President Bush says he would have done anything in his power to stop the 9/11 attacks if he would have had more information in advance. But he says the briefing memo contained little in the way of specific information about al-Qaida's threats in the weeks before the attacks.

?And the PDB [President's Daily Intelligence Brief] was no indication of a terrorist threat. There was not a time and place of an attack, the President said. ?And it said Osama bin Laden had designs on America. Well, I knew that.?

The 9/11 commission was established by Congress and the White House in 2002 to find out what went wrong in the lead-up to the terrorist attacks and how the country can better defend itself in the future. It is expected to release its final report by the end of July.