The 2007 attack in Baghdad left 12 dead, including a Reuters journalist and his driver. In the video, released by WikiLeaks as "Collateral Murder," the American helicopter crew can be heard laughing and referring to Iraqis as "dead bastards."
Manning supporters say whoever released the footage is a hero who should be protected as a whistle-blower.
The Bradley Manning Support Network also objected to the decision to close portions of the hearing, saying in a statement Monday it was "deeply troubled" by "the imposition of an unexplained media blackout without any avenue for redress."
Earlier Monday, Manning's roommate in Iraq testified that Manning "probably planned on getting out of the military."
Spc. Eric S. Baker said Manning had told him the Army "wasn't for him." He also said Manning used a computer "quite often."
"When I'd wake up in the middle of the night, he'd be on the computer," Baker said.
In cross-examination, Baker acknowledged to Manning's attorney that the two weren't friends. Baker affirmed that Manning had made statements that led him to believe he was gay, and Baker responded that it would be best if they didn't talk.
On Sunday, Shaver testified that he found thousands of classified files on Manning's computer. They included 10,000 State Department cables and video of the helicopter attack.
On Saturday, Capt. Steven Lim, one of Manning's superiors in Iraq, identified searches he believed the analyst conducted on government databases with keywords that included "WikiLeaks," "Julian Assange" and "Guantanamo Bay detainee assessments."
During the weekend, Manning's attorneys sought to portray Manning as a troubled young man who struggled with gender identity disorder, was isolated from his fellow soldiers and should not have been given access to the classified materials.
Special Agent Toni Graham testified that Manning kept a folder of articles on gender identity disorder in his sleeping quarters, including one partially titled "flight into hypermasculinity." Special Agent Calder Robertson said Manning maintained an alter-ego called "Breanna Manning."
Lim confirmed details of an email Manning sent to an officer that included a picture of Manning dressed as a woman. The email included a plea that his confusion about his gender was preventing him from thinking clearly.
Lim testified that he did not learn of the email until after Manning was detained, but said its contents were alarming enough to merit removing his security clearance.
Manning's team also has suggested that computer security at the facility in Iraq where he worked was lax, and rules routinely were broken.
Prosecutors have sought to emphasize that Manning was well trained in how to handle sensitive information and knew not to distribute it.