Adrian Lamo at the home of his parents in Carmichael, California in spring 2010. Photo: Ariel Zambelich/Wired.com

FT. MEADE, Maryland - Accused WikiLeaks source Bradley Manning wasn't the only person that convicted hacker Adrian Lamo reported to the authorities for allegedly helping WikiLeaks, according to testimony in a Saturday military hearing concerning Manning's alleged leaking.

In May 2010, Lamo gave the FBI incriminating chat logs with Bradley Manning, leading to Manning's arrest on charges that he aided the country's enemies when he leaked classified and sensitive documents. When Wired reported his actions, Lamo instantly became persona non grata among a large swath of the hacker community, which largely supports WikiLeaks and almost uniformly detests those who cooperate with authorities.

In court testimony Saturday, a government witness testifying against Manning said that Lamo subsequently contacted authorities in July 2010 to say that he'd learned through online chats that a person named Jason Katz who worked at a Department of Energy lab had tried to help WikiLeaks decrypt a video of the 2009 Garani incident, in which U.S. warplanes allegedly killed nearly 100 Afghan civilians.

Katz was fired from his job at the DoE's Brookhaven National Laboratory in March 2010, one month prior to publication of the Collateral Murder video, for engaging in unspecified "inappropriate computer activity," Special Agent Mark Mander, an investigator with the Army's Computer Crime Investigative Unit, divulged in court.

After Lamo's tip, the government searched Katz's former workstation, and found an encrypted and password-protected file, which investigators opened after the military provided the government password for the Garani video file, according to testimony.

The Brookhaven National Laboratory, which is run by a private company under contract with the Department of Energy, noted the departure of a physicist named Jason Katz in its March 12, 2010 newsletter. The arrival of a physicist named Jason Katz was noted in a February 13, 2009 newsletter.

According to Mander, Katz had allegedly been bragging in an online chat with an unspecified person about trying to decrypt the Garani video. It was unclear from Mander's testimony if Katz had been chatting directly with Lamo or with another person.

Lamo confirmed Mander's account of the incident to Wired.com following the witnesses testimony. He clarified that he was never in direct contact with Katz, but would not elaborate on how he became aware of Katz's chat.

"In protecting sources and methods, I am hesitant to disclose how I became aware of this individual," he said in a phone call, adding cryptically that "the means of which I became aware of his activities were not a human interaction."

Lamo is preparing to testify as a witness at the hearing but has not been told yet when he will be called. "Toward the end of the proceeding," he said, noting that the government has been preparing him for testimony by explaining the basic procedures of the Article 32 hearing.

WikiLeaks hinted in January 2010 that it had the Garani video and that it was in the process of breaking the encryption.

Instead, WikiLeaks published the so-called Collateral Murder video of a U.S. helicopter attack in Iraq where two Reuters employees were killed, and two children seriously wounded. Manning allegedly told Lamo that he gave that previously unseen footage and the password to unlock it to WikiLeaks. After that video was made public, WikiLeaks founder Julian Assange told reporters that his organization still had the Garani video and would publish it as well, but the video has never been published - presumably because the organization has been unable to break the encryption.

Encrypted files can be opened via brute-force computing, using powerful computers or sets of computers to repeatedly guess possible passwords. But brute-forcing a file encrypted with a strong algorithm and a complicated password can take up to decades, even with the world's most powerful computers, such as those used in government research labs.

The Garani attack became an international incident, and while the Pentagon said it would show the video to reporters in conjunction with the release of the findings of an investigation, the military never made good on the video offer.

Secretary of State Clinton, President Obama, and other American leaders apologized after American F/A-18 jets and a B-1 bomber dropped munitions on suspected Taliban positions during a firefight in the village of Garani. As many as 97 civilians may have lost their lives, according to the Afghan Independent Human Rights Commission.

But the U.S. military remained steadfast that the attacks on a set of Garani compounds were justified — and said that footage taken from the B-1′s weapon sight would "prove [t]hat the targets of these different strikes were the Taliban," as Petraeus told NPR. The video allegedly shows that two groups of adults going inside the compounds targeted by the B-1. Additional footage shows women and children streaming into other buildings that were not bombed.

WikiLeaks alleges the video is among the files taken from WikiLeaks and destroyed by disgruntled former spokesman Daniel Domscheit-Berg, who left to set up a competing leak site called OpenLeak, saying that Assange wasn't responsible enough to have the documents.

Updated 8:13pm EST: Added comment from Adrian Lamo.

Additional reporting and writing by Ryan Singel