The screws are tightening.
After months of legal work, a jury trial, eight guilty verdicts and vehement opposition from the president of the United States, special counsel Robert Mueller has unlocked what he sees as the "key" to a potential conspiracy case against President Donald Trump, legal experts said.
The president's former campaign manager, Paul Manafort, who was convicted last month on a range of felony charges by a jury in Virginia, has agreed to cooperate with investigators examining possible links between the president's 2016 campaign and the Kremlin ahead of a planned trial in Washington, D.C., on a host of other charges.
Sol Wisenberg, deputy to Kenneth Starr during the 1990s Whitewater investigation of President Bill Clinton, said that in the previous pleas that Mueller has obtained from top Trump associates, including former national security advisor Michael Flynn, there were few grounds on which to base a conspiracy case. With Manafort's cooperation, he said, that could change.