The Justice Department drops criminal case against Michael Flynn

The Justice Department has abandoned its prosecution of President Donald Trump’s former national security adviser Michael Flynn, throwing in the towel on one of the most prominent cases brought by special counsel Robert Mueller.

Flynn pleaded guilty in 2017 to lying to the FBI about his dealings with the Russian ambassador to the U.S. But department officials, including Attorney General William Barr, concluded in light of recently disclosed evidence that the FBI’s questioning of him just four days after Trump’s inauguration lacked a proper investigative basis.

The abrupt move came moments after the top prosecutor in the case against withdrew abruptly and without explanation. Brandon Van Grack, who served as one of special counsel Robert Mueller's top lawyers and remained on the Flynn case even after Mueller's office closed down, signaled his exit from the case in a terse, one-sentence filing with U.S. District Court Judge Emmet Sullivan Thursday afternoon.

After switching defense teams last year, Flynn began leveling a series of increasingly strident attacks on the prosecution, culminating in a motion in January to withdraw his guilty plea altogether.

The move by Van Grack came four days before a court deadline for the prosecution to respond to an ongoing effort by Flynn's defense team to have the case against him dismissed on the grounds of egregious government misconduct.

In recent weeks and months, Flynn's defense — headed by Texas lawyer Sidney Powell — had escalated its attacks on Van Grack personally, alleging that he withheld evidence favorable to Flynn in defiance of an order from Sullivan requiring the prosecution to turn over such material.

A defense filing two weeks ago accused Van Grack of "incredible malfeasance" and of coercing Flynn's guilty plea in the fall of 2017 by making "baseless threats" to indict Flynn's son, Michael G. Flynn Jr.

Van Grack was the only member of Mueller's prosecution squad to take up a Justice Department leadership position after the Russia probe closed down, assuming a role last March overseeing the department's enforcement of the foreign-agent registration laws and other efforts to combat foreign influence in the U.S.

It was not immediately clear Thursday whether Van Grack was continuing in that capacity or leaving his post altogether. The court filings he submitted Thursday still bore his title as chief of the Foreign Agent Registration Act Unit.

The filings also did not indicate whether Van Grack was directed to withdraw from the Flynn case or elected to do so.