Mueller set a legal trap to prevent Trump from pardoning Flynn: ex-prosecutor

A former federal prosecutor explained why President Donald Trump should be worried about Mike Flynn's possible cooperation with the special counsel -- and why he may not be able to pardon his former national security adviser.

Flynn's lawyers notified the president's legal team Wednesday that they would no longer share information about the case, according to a New York Times report, and former prosecutor Renato Mariotti broke down what that means.

"Defense attorneys representing individuals that are under investigation typically agree to share information with each other about what they've learned from the government," Mariotti tweeted.

"The government tries to reveal as little as possible about what it's doing to the defense," he added, "so defense attorneys try to glean as much as they can from their brief conversations with prosecutors and from the questions their clients are asked during interviews."

Mariotti, who's running for Illinois attorney general, said those "nuggets of information are valuable" and usually provide the basis of news reports on special counsel Robert Mueller's investigation of Trump campaign ties to Russia.

Defense attorneys representing clients in the same investigation usually enter into a joint defense agreement, which can be formal or informal, he explained, and makes their statements to one another privileged.

This week's news indicate Flynn and his lawyers no longer believe Trump will pardon the disgraced national security adviser or his son Mike Flynn Jr., or that they believe the father-son duo could be convicted of state crimes beyond the reach of a pardon, Mariotti tweeted.

"A deal for Flynn would likely mean that Mueller would accept a guilty plea to a single felony charge and would potentially recommend a reduced sentence depending on the extent of his cooperation," Mariotti said. "It is unlikely to result in complete immunity."

The former prosecutor said cooperating witnesses are required to answer all questions on all subjects related to the investigation, so Flynn could lengthen the special counsel probe.

"Trump lawyer Ty Cobb's prediction that the entire investigation could wrap up shortly after the new year is looking worse by the minute," Mariotti said.

But what about a pardon, which presidents have great leeway to do?

"One answer could be that a pardon of Flynn could be used by Mueller as evidence of Trump's 'corrupt intent' to prove obstruction, because it could indicate Trump's strong desire to relieve Flynn of criminal liability," Mariotti said.

According to former FBI director James Comey, the president asked him to wind down the investigation of Flynn's ties to Russia, saying his former national security adviser was a "good guy."

That could form the basis of an obstruction of justice charge against the president during an impeachment proceeding.