WASHINGTON (AP)--The Senate report on the CIA's post-Sept. 11 interrogations shows how a rigorous examination of a secret agency can expose misconduct, incompetence and bureaucratic spin, even to those who question the investigation's assertion that torture did not work.

The review also highlights how rare such examinations are, and it raises this question: How well run are other CIA programs, such as targeted killing with drones or the secret effort to train and arm Syrian rebels?

Congressional intelligence committees have long been accused of being "captured" by the agencies they oversee. When the committees do expose and correct problems, it almost always happens behind closed doors. The Senate report's 518-page summary, made public in December, was a rare instance of an oversight committee trying to hold the CIA accountable in a public way.

Particularly unusual was that its findings came from 6 million pages of the sort of internal CIA records that few outsiders, including committee staffers, ever get to see.

The report was written by Democrats, and its chief conclusion that brutal interrogations failed to produce unique intelligence is disputed by most Republicans and by the CIA. Since most of the CIA records remain secret, there may always be disagreement about whether detainees, after being tortured, provided information that was important to the hunt for Osama bin Laden, for example, even if it's clear that CIA got much of its intelligence in that case from other sources.

Using cables, emails, internal memos and instant message chats, Democratic Senate investigators forced the spy agency to publicly admit that it mismanaged the interrogation program, failed to punish misconduct and detained people it shouldn't have. The report documented dozens of instances of the CIA exaggerating the fruits of brutal interrogations to justify its actions, including in inaccurate testimony to Congress about the bin Laden case.

The CIA "simply failed to live up to the standards that we set for ourselves and that the American people expect of us," CIA Director John Brennan told reporters at agency headquarters in December.

Yet the same committee that looked deeply into torture has never taken a similar look at what is now the premier counterterrorism effort, the CIA's drone program, say congressional officials who were not authorized to discuss the matter.

Nor have the intelligence committees been able to examine cables, emails and raw reporting to investigate recent perceived intelligence lapses, such as why the CIA failed to predict the swift fall of Arab governments, Russia's move into Ukraine or the rapid military advance of the Islamic State group.

The torture probe was unique in its depth.

Michael Colaresi, a Michigan State political scientist who has written about how Western democracies police their spy agencies, says access to internal agency records should be a regular feature of congressional intelligence oversight. The U.S. once led the way in keeping tabs on its spies, but now several Western nations conduct more thorough oversight of their intelligence agencies, he said.

"Intelligence oversight is necessary to reassure the public that if there is bad policy being done behind the veil of classification, it's going to be revealed," he said.