Lieutenant General Michael Flynn is a key figure in Trumpgate. He was a senior member of Trump’s transition team, serving as one of his national security advisors during the transition period.
When Trump took office, he appointed Flynn as National Security Advisor, which lasted for 24 days until Flynn was fired for private discussions he had with Russian ambassador Sergey Kislyak.
Flynn and Kislyak discussed the lifting of US sanctions against Russia, which had just been imposed by then President Barack Obama. They also discussed a UN resolution about Israeli settlements. Both conversations undermined US plans and policy at the time.
It was also discovered that Flynn had secretly accepted money from Turkey and was acting as an unregistered agent on their behalf but failed to mention any of this.
In December of 2017, Flynn pleaded guilty to the charge of lying to the FBI and, in a plea bargain arrangement, agreed to cooperate with investigation being led by Robert Mueller.
On December 18th, 2018, Lieutenant General Michael Flynn appeared in court for a sentencing hearing on charges that he lied to the FBI. Trump and his crew started spreading rumors that the FBI had entrapped Flynn, that they tricked him into telling multiple lies at multiple times to multiple people. There were even opinions that the judge was going to dismiss the charges.
At the actual hearing, Judge Emmet Sullivan ripped Flynn a new one. He actually asked the prosecutors if they’d considered charging Flynn with Treason.
A request to delay sentencing was granted by the court so Flynn could try to redeem himself to America and Judge Sullivan by continuing to cooperate with Mueller’s investigation.