Flynn’s case was a signature case brought by special counsel Robert Mueller.
Prosecutors maintained Flynn lied to the FBI during a January 2017 interview about his conversations with the Russian ambassador. Flynn admitted to lying, plead guilty, then asked to withdraw the plea.
Flynn became a key witness for Mueller in the special counsel investigation of ties between Russia and the 2016 Trump campaign.
The startling decision adds to Democratic complaints that Attorney General William Barr is excessively loyal to the president.
In court documents filed Thursday, the Justice Department said it is dropping the case “after a considered review of all the facts and circumstances of this case, including newly discovered and disclosed information.”
The Justice Department said it had concluded that Flynn’s interview by the FBI was “untethered to, and unjustified by, the FBI’s counterintelligence investigation into Mr. Flynn” and that the interview was “conducted without any legitimate investigative basis.”
U.S. attorney Jeff Jensen said in a statement: “Through the course of my review of General Flynn’s case, I concluded the proper and just course was to dismiss the case. I briefed Attorney General Barr on my findings, advised him on these conclusions, and he agreed.”
Flynn’s lawyers cited newly disclosed FBI emails and notes last week to allege that Flynn was improperly trapped into lying when agents interviewed him at the White House days after Trump’s inauguration.