WASHINGTON >> A list of key players relevant to the Special Counsel investigation into former Trump administration National Security Adviser Michael Flynn:

Michael T. Flynn — A retired U.S. Army Lt. General and former director of the Defense Intelligence Agency during the Obama administration, Flynn served for less than a month as President Donald Trump’s first national security adviser. He was fired in mid-February by Trump for misleading Vice President Mike Pence and other officials about his phone discussions with Russia’s ambassador, Sergey Kislyak. Flynn’s misleading statements about his Russia contacts and his 2016 consulting work for a Turkish client both came under scrutiny by Special Counsel Robert Mueller’s investigation. Flynn admitted Friday to one count of making false statements about his contacts with Kislyak.

Sergey Kislyak — As Russia’s ambassador to the U.S., Kislyak attended the 2016 Republican national convention in Cleveland, where Trump was nominated as the party’s presidential candidate. During the campaign, Kislyak met several Trump aides, including then-Sen. Jeff Sessions and foreign policy adviser Carter Page. After Trump’s election, Kislyak spoke by phone several times with Flynn in late December, and reportedly discussed economic sanctions put in place by the Obama administration. The calls were monitored by U.S. intelligence agencies and days after Trump took office in January, Flynn reportedly lied to FBI agents interviewing him about the Kislyak talks. Kislyak was replaced as Russia’s ambassador in July.

Vice President Mike Pence — After media revelations in mid-January of Flynn’s talks with Kislyak, Flynn told Pence that his conversations with the Russian did not address U.S. sanctions against Russia. In several television news show appearances, Pence said that Flynn had assured him that he and Kislyak did not discuss sanctions. The White House later explained Flynn’s firing by saying he had lost the trust of both Trump and Pence.

President Donald Trump — After naming Flynn to head the National Security Council in January, Trump reluctantly fired him less than a month later. FBI Director James Comey later testified that during an Oval Office meeting the day after Flynn’s firing, Trump appeared to ask him to end the FBI’s inquiry, reportedly saying: “I hope you can let this go.” Trump has repeatedly denied the comment or that he tried to interfere in the probe.

James Comey — The former FBI director, whose firing in May precipitated the appointment of Robert Mueller as special counsel, has said that Trump asked him during a private Oval Office encounter if he could see his way to letting the Flynn investigation go, and told him that Flynn was a good man. Comey has said he found the request concerning and documented it in an internal memo, summaries of which were later disclosed to members of the media. The White House has denied that the conversation occurred as Comey described.

Sally Yates — As acting attorney general, Yates and another Justice Department official went to the White House on Jan. 26 to warn White House counsel Don McGahn that Flynn was potentially compromised and vulnerable to blackmail because of discrepancies between the public accounting of the Kislyak conversation and what actually occurred. White House officials, including Pence, had stated publicly that Flynn had not discussed sanctions with Kislyak but Yates has said she advised McGahn that there were factual problems with that account. She has said she expected the White House to take action.

Michael G. Flynn — Michael Flynn Jr., as he is known, accompanied his father on his 2015 trip to Moscow. Flynn Jr. worked for his father’s company as part of its 2016 research aimed at developing a criminal case against Fethullah Gulen, a Turkish Muslim cleric whose extradition from the U.S. has been sought by Turkey’s government. Flynn’s son was paid $12,000 for unspecified “administrative support” under the Turkish contract. Flynn Jr. also acted briefly as his father’s chief of staff during the transition, but was forced to resign after his frequent tweets on conspiracy theories.

KT McFarland — The former deputy national security adviser in the Trump administration, and former Fox News analyst, was nominated in May to be ambassador to Singapore. According to two former transition officials, McFarland was referenced in court papers Friday as the unnamed Trump transition team member who spoke with Flynn last December about what, if anything, to say about sanctions that had just been imposed by the Obama administration in response to election meddling.