Updated

One week before key testimony by the intelligence community, a new congressional report based on more than 40 interviews with former senior intelligence and FBI (search) officials, paints a mixed picture of progress at the agency.

An issue at the heart of the report, which investigated the agency for six months, is that cultural change is from law enforcement to a domestic intelligence agency designed to disrupt terrorist attacks.

"They believe the culture of the FBI is so entrenched and it has so little experience over the long-term gathering of intelligence for the purposes of preventing, that they are skeptical they can make the cultural change," said Alfred Cumming, co-author of the Congressional Research Service (search) study.

While the report notes advances such as increasing intelligence operations, training analysts and enhancing recruitment, the study reports limited progress on intelligence-sharing, a key structural problem that led to the Sept. 11, 2001, terror attacks.

The report comes as the Sept. 11 commission begins to consider whether to recommend changes to FBI's domestic intelligence role in its final report.

Click here to watch a report by Fox News' Catherine Herridge.