The US soldier accused of providing classified files to WikiLeaks told his aunt a leaked video of a helicopter attack in Iraq that killed civilians would cause a "big splash," she said in a statement at his court-martial on Tuesday.
Private First Class Bradley Manning's aunt, Debra Van Alstyne, told Army investigators about his comment when they talked to her at her Potomac, Maryland, home in June 2010, after his arrest, according to a statement read into the trial record.
Manning, 25, is on trial for allegedly leaking more than 700,000 files, videos and other documents to WikiLeaks, an anti-secrecy website. The largest release of classified data in US history included a gunsight video from a 2007 Apache helicopter attack in Baghdad in which civilians were killed, including two Reuters staffers.
In the statement read by prosecutor Major Ashden Fein, Van Alstyne said an investigator collected a digital camera data card that was found to contain some of the leaked Iraq battlefield reports and the Apache video.
Manning called her after his arrest in May 2010 and asked if she had watched the helicopter video, Van Alstyne said in the statement. She said he told her it would be "big news" and that it would make "a big splash in America."
The soldier is accused of leaking the files while serving in Iraq as an intelligence analyst in 2009 and 2010. The 21 charges against him include aiding the enemy and he could face life imprisonment without parole if convicted.
Lawyers for Manning have described him as naive but well-intentioned in wanting to show the American public the reality of war in Afghanistan and Iraq.
Earlier on Tuesday, a Marine Corps computer security expert testified that WikiLeaks founder Julian Assange had solicited secret US military information during a 2009 conference in Berlin.
Marine Staff Sergeant Matthew Hosburgh, the expert, said he attended the conference, where Assange encouraged the release of "not only classified information, but also trade secrets and anything of that nature."
Assange has taken refuge in the Ecuadorean Embassy in London as he faces criminal sexual charges in Sweden. Assange, an Australian, says the charges are reprisal for WikiLeaks publishing information embarrassing to the United States and other governments.
Prosecution witness David Shaver, a government digital media forensic analyst, testified that he intercepted "chat logs" between Manning and computer threat analyst and hacker Adrian Lamo, in which Manning referred to information leaked to WikLeaks.
The chat logs, which are digital records of data exchanges over the Internet, show Manning talking about "Gitmo papers" and a 2009 US airstrike in the Afghani village of Garani that killed 26 civilians, he said.
Lamo later reported Manning to US authorities as the person responsible for disclosing the information to WikiLeaks.
Defense attorneys questioned Shaver about gaps and possible inaccuracies created by the computer programs he used to track the chat logs.
David Coombs, Manning's attorney, tried to show that, although Manning might have had access to the classified material, a computer believed to have been used to transfer information to WikiLeaks belonged to Jason Katz, a former Brookhaven National Laboratory computer expert.
Katz was fired in March 2010 from the Department of Energy laboratory for "inappropriate computer activity" about a month before WikiLeaks posted the Apache video.
Shaver said under defense questioning that there were no telephone calls, emails or other evidence to link Manning with Katz.
Manning's trial coincides with the unauthorized release last week of information by a former National Security Agency contractor of widespread government telephone and Internet usage surveillance of private US citizens not suspected of crimes.