CIA Didn't Share Info About 9/11 Hijackers

July 24 -- If San Diego FBI agent Steven Butler had known what the CIA knew about possible terror attacks, he may have had the best chance to stop the Sept. 11, 2001, hijackers, investigators told ABCNEWS.

Butler had two of the hijackers, Nawaf Alhamzi and Khalid Al-Midhar, under his nose for some 18 months, but neither he, nor anyone in the FBI, was warned by the CIA.

The CIA had tracked Alhamzi and Al-Midhar to California after the men were photographed at an al Qaeda planning meeting in Malaysia in January 2000 where, it was later determined, terrorists were plotting the attack on the USS Cole.

Alhamzi and Al-Midhar then moved to San Diego, where the FBI could have monitored them. The two future hijackers actually rented rooms in the house of one of Butler's informants, Abdussattar Shaikh, a leader at the local mosque, who also helped get them a computer and a car.

"We know for a fact that that car was used to travel from San Diego to Phoenix, to meet up with Hani Hanjour …, who [was] another pilot who [was] taking flight training," said Jack Cloonan, a former FBI agent who is now an ABCNEWS consultant. "This is a window of opportunity you are seldom presented with."

Hanjour would end up with Alhamzi and Al-Midhar on American Airlines Flight 77, the jet that smashed into the Pentagon shortly after departing from Dulles airport outside Washington.

A government report on the Sept. 11 attacks, which was prepared by a joint House-Senate committee and released today, says the FBI's informant knew that Alhamzi and Al-Midhar were going to flight school in Arizona but never told his FBI handler, Butler, who was in the dark about the significance of the two men.

"The informant's contacts with the hijackers, had they been capitalized on, would have give the San Diego FBI field office perhaps the Intelligence Community's best chance to unravel the September 11 plot," the report says.

"Given the CIA's failure to disseminate, in a timely manner, intelligence information on the significance and location of Al-Midhar and Alhamzi, that chance, unfortunately, never materialized."