Questions about lax computer security and the judgment of his superior officers dominated the third day of a pretrial military hearing for Pfc. Bradley Manning, the Army intelligence analyst charged with turning over government secrets to WikiLeaks.

In addition, two of the Army’s witnesses — among Manning’s superiors — declined to testify Sunday on the grounds that their testimony might incriminate them.

Manning, 24, faces 22 charges, including “aiding the enemy” for allegedly turning over information to the anti-secrecy Web site Wiki­Leaks.

The hearing, in a military courtroom at Fort Meade, will determine whether the government has sufficient evidence to proceed to a court-martial. Manning could face life in prison or the death penalty.

On Sunday, witnesses spoke of the loose computer security features of Forward Operating Base Hammer in Iraq, and Manning’s defense attorney argued that his client’s early displays of troubling behavior should have led to his security clearance being revoked long before WikiLeaks received any material.

Manning was reportedly alternately violent and withdrawn, and in at least one instance he told a superior that he struggled with gender identity. Manning is said to have sent a photograph of himself dressed as a woman to the superior.

One intelligence officer testified Sunday about unauthorized programs being stored on the computer system’s shared drive along with music, movies and games. Another witness said there was nothing to stop soldiers from burning information from the classified network onto a compact disc other than “trust that the soldier would do what is right.”

Capt. Thomas Cherepko, the officer who managed information systems, outlined violations on the classified network. Cherepko said he reported the problems to his supervisors but analysts were never disciplined.

Army prosecutors continued their argument that Manning was well-trained in handling classified information.

Manning told Allen Millman, a field software engineer contractor at FOB Hammer, “If people really knew what I could do with a computer they would be amazed,” Millman said.

Capt. Casey Fulton detailed Manning’s work as a junior analyst at Forward Operating Base Hammer, saying she relied heavily on his talents and routinely had him search classified databases.

She also was questioned about the video of an Apache helicopter firing on civilians that WikiLeaks posted in April 2010.

“I asked analysts if they had seen the video. It didn’t make the military look very good. I engaged them in what they thought of it. Manning asked me if the leaked video was the same video as the one on our shared drive. I said, ‘no way,’ ” Fulton testified.

Manning later sent Fulton a link to the video on the shared network drive as well as the link to the WikiLeaks video to show they were the same.

Manning is alleged to have sent the video to WikiLeaks.

Sgt. Chad Madaras, who worked with Manning at FOB Hammer, described him as moody and unreliable. Madaras recalled incidents when Manning would slam his fists or books down on his desk and said Manning sometimes would be completely unresponsive, staring blankly at his work station.

Fulton also detailed several incidents that she said should have resulted in Manning’s security clearance being revoked.

In December 2009, she said, Manning overturned a table during an argument. Had the event been reported, it would have been the basis for suspending his access to classified material at FOB Hammer, she said.

Two of the Army’s witnesses, however, appeared only to decline to testify.

Sgt. 1st Class Paul Adkins, gray-haired and with round wire-rimmed glasses, was the superior officer to whom Manning e-mailed a photo of himself dressed as a woman and described how his struggle with gender identity was impairing his ability to work.David Coombs, Manning’s chief defense attorney, argued that Adkins could be granted immunity, but that request was denied and Adkins was dismissed as a witness.

Adkins invoked his Article 31 rights against self incrimination.

Kyle J. Balonek, the warrant officer who was in charge of the day shift at FOB Hammer and witnessed some of Manning’s erratic behavior, also invoked his right to remain silent.

In April 2010, WikiLeaks posted a video of an Apache helicopter strike in which civilians were fired upon by U.S. forces. In summer 2010, several news organizations published the daily field reports from the wars in Iraq and Afghanistan, and in November 2010, WikiLeaks and several news organizations began publishing more than 250,000 State Department cables.

Special Agent David Shaver of the Army’s Computer Crimes Investigative Unit was the last of the seven witnesses to testify Sunday. In the archives of Manning’s two work stations, Shaver was able to locate copies of Guantanamo detainee assessments, tens of thousands of State Department cables, the Apache helicopter video and other material.

Manning was arrested in Iraq in May 2010 and charged in July with transferring classified information onto his computer. He was moved that month to the jail at the Quantico Marine Corps Base, where he was held in solitary confinement until his transfer to Fort Leavenworth’s medium-security facility in April 2011.

The hearing’s investigating officer, Lt. Col. Paul Almanza, will make a recommendation in the coming weeks as to whether Manning should face a court-martial. A “convening authority” will make the decision to refer the case to court-martial or not, and on what charges.

A legal military adviser said new charges could be recommended and other charges dropped when Almanza submits his report to the authority. The hearing is expected to last three more days.