"The government has now confirmed what has always been clear: No one tried to wiretap or bug Senator Landrieu's office," O'Keefe wrote.
He and three others were charged with maliciously interfering with a telephone system operated and controlled by the U.S. government, which could result in a sentence of up to 10 years in prison and a $250,000 fine, CBS News' Bob Orr reports. The men are currently free on $10,000 bail.
An attorney for one of the men said Thursday they were not trying to wiretap Sen. Mary Landrieu's office but simply record embarrassing hidden camera footage of her staff.
O'Keefe made the same case in his statement today: "On reflection, I could have used a different approach to this investigation, particularly given the sensitivities that people understandably have about security in a federal building. The sole intent of our investigation was to determine whether or not Senator Landrieu was purposely trying to avoid constituents who were calling to register their views to her as their Senator."
A senior federal law enforcement official told the Associated Press on Thursday that investigators were still are pressing ahead to determine what the men's motives were in Landrieu's office. The official spoke on condition of anonymity because the investigation is ongoing.