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In January 2010 when Army intelligence analyst Bradley Manning was allegedly contemplating leaking thousands of classified documents to WikiLeaks, he visited friends in Boston, who brought him to a party at Boston University’s BUILDS hacker space.

Frontline, which is airing a documentary about Manning and WikiLeaks on May 24, has obtained a video showing Manning at the party. [Disclosure: Threat Level's Kevin Poulsen and Kim Zetter were interviewed for the documentary.]

At the time of the party, Manning was on a two-week leave from his assignment in Iraq. It was at one point during this trip that he told friend Tyler Watkins that he’d gotten his hands on classified information that he was thinking about leaking, according to Watkins. “He wanted to do the right thing,” Watkins said in an interview with Threat Level last June. ”That was something I think he was struggling with.”

The video shows Manning at the BUILDS party, small in stature compared to the hackers around him, leaning against a table while chatting with friend Danny Clark (in a red t-shirt at Manning’s left).

The party was hosted by David House, founder of the hacker space, who now helps run the Bradley Manning Support Network. House tells Frontline that Manning didn’t stand out and didn’t strike him as remarkable at the time.

The government is known to have interviewed some of Manning’s Boston-area friends after his arrest in May 2010, including House and Clark. Last month, the government reportedly issued a grand jury subpoena to one of Manning’s friends, who has not been publicly identified, but lives in Boston. House has said he did not receive a subpoena.

According to the charges against Manning, he allegedly downloaded what’s now known as the Iraq and Afghanistan war logs between December 31, 2009 and January 8, 2010 – prior to his Boston visit – and leaked them on or before February 5. The time frame leaves open the possibility that Manning might have brought the war logs with him to the U.S. to leak them from a network not subject to the Army’s monitoring.

At the time of the BUILDS party, Manning had already leaked an encrypted copy of a classified Army video, BE22 PAX.wmv, according to the charges. That file is likely a video of the notorious Gharani massacre in Afghanistan. WikiLeaks acknowledged having that video on January 8, 2010, but has never published it.