FILE - In this March 8, 1951 file photo from left, Harry McCabe, Deputy U.S. Marshall; Julius Rosenberg and wife, Eithel Rosenberg and Anthony H. Pavone, Deputy U.S. Marshall in New York. Julius Rosenberg, 33-year old electrical engineer from New York City and his wife were on trial on charges of conspiracy to commit espionage during World War II, involving U.S. atomic secrets. The sons of convicted spy Ethel Rosenberg are asking President Barack Obama to exonerate their mother. Michael and Robert Meeropol were presenting a letter at the White House on Thursday, citing unsealed court records they say cast doubt on their mother‚Äôs guilt. (AP Photo)