lens. "nightly news" begins now. >> from nbc world headquarters in new york, this is "nbc nightly news with brian williams." >>> good evening. i'm lester holt in for brian. an international manhunt for the 29-year-old man who says he's the one who exposed the government secret surveillance program. what he told "the guardian" newspaper in a story published last week caused a firestorm of controversy over privacy and national security. edward snowden has been identified as a contractor who worked at the national security agency, and yesterday from halfway across the world, he stepped from the shadows, admitting he was the leak. and tonight, the u.s. government is hot on snowden's tail as it investigates whether or not he broke the law by sharing classified information. nbc's andrea mitchell is working the story for us tonight from washington. andrea? >> reporter: lester, good evening. they have launched the manhunt for. the 29-year-old nsa contractor, edward snowden, has turned the massive national security agency inside out. federal agents at the home today of edward snowden's mother in ellicott city, maryland, only