FORT MEADE, Md. - A computer-crimes investigator testified Sunday that he found more than 10,000 diplomatic cables and other sensitive information on the work computer of the Army private charged with spilling a mountain of secrets to WikiLeaks.

Moreover, Special Agent David Shaver told a military hearing he discovered evidence that someone had used the computer to streamline the downloading of the cables with the apparent aim of "moving them out."

It was the government's first hard evidence linking Pfc. Bradley Manning with the wealth of confidential government information that showed up on WikiLeaks: battlefield reports from Iraq and Afghanistan, diplomatic communications, a military video showing a U.S. helicopter attack that killed 11 men, and more.

Shaver's appearance capped the third day of a hearing that will determine whether Manning will be court-martialed on 22 charges, including aiding the enemy. The testimony was potentially the most damaging so far.

Shaver said the material he found at the intelligence analyst's workstation in Iraq was all linked to the user name bradley.manning or Manning's user profile.

He said he examined two computers assigned to Manning while he was working in Baghdad in 2009 and 2010.

He said the other machine contained evidence that someone had conducted more than 100 searches using the keywords WikiLeaks and Julian Assange, the organization's leader.

The terms seemed "out of place" on a computer used for analyzing intelligence about Iraq, said Shaver, who is to be cross-examined by Manning's defense Monday.

Shaver told the hearing that in addition to the cables, he found assessments of Guantanamo Bay terrorist detainees and several versions of the 2007 helicopter attack video on Manning's computer.

Manning's lawyers have neither acknowledged nor denied that he was behind the leaks.

Instead, they have pressed the government to explain why Manning remained entrusted with access to highly sensitive information after showing hostile behavior to those around him. A supervisor who might have shed light on that question Sunday refused to testify.

Manning, 24, a native of Crescent, Okla., could face life in prison if convicted.

Manning's defense sought to build on its case that his supervisors on the Second Brigade Combat Team should have seen enough red flags to suspend or revoke his access to secret information months before the leaks.

Capt. Casey Fulton, an Army intelligence officer, testified Sunday it was impossible to supervise analysts such as Manning constantly. "You have to trust that they'll safeguard the material the way that they've been taught," she said.

Manning is accused of illegally leaking secret information that surfaced on the antisecrecy website WikiLeaks. The breach rattled U.S. foreign relations and, according to the government, imperiled valuable military and diplomatic sources. Defense attorneys argue the leaked material did little or no damage to U.S. interests.