May 17, 2017: Former FBI Director Robert Mueller is appointed as special counsel.

Oct. 30, 2017: Mueller makes his first public move, obtaining indictments against Paul Manafort and Rick Gates, the former chairman and deputy chairman of Donald Trump's presidential campaign, respectively. They're charged with money laundering, tax evasion and other crimes related to their work for Ukraine's pro-Russia government. Mueller also releases a guilty plea from George Papadopoulos, a former low-level foreign policy adviser to Trump's campaign, who admitted to lying about his overseas contacts.

Dec. 1, 2017: Michael Flynn, Trump's former national security adviser, pleads guilty to lying to the FBI about his conversations with the Russian ambassador in Washington during the presidential transition.

Feb. 16, 2018: Thirteen Russians are indicted for allegedly interfering in the 2016 campaign with stolen identities, fake campaign events and social media accounts. Mueller also charges three Russian companies, including the St. Petersburg-based Internet Research Agency, which is described as a Kremlin-connected "troll factory."

Feb. 20, 2018: Alex van der Zwaan, a former London-based Dutch lawyer, pleads guilty to lying to federal agents about his work with Manafort and Gates on a controversial report.

Feb. 23, 2018: Gates pleads guilty to charges of conspiracy and lying to federal agents, and he agrees to cooperate with the special counsel's office.

April 9, 2018: Using evidence passed along by Mueller, the U.S. Attorney's Office in Manhattan sends FBI agents to raid the home, office and hotel room of Michael Cohen. Prosecutors later tell a federal court that Cohen, Trump's longtime personal lawyer and an executive vice president of the Trump Organization, is the subject of a "monthslong investigation" into "criminal conduct that largely centers on his personal business dealings."

July 13, 2018: Twelve Russian military intelligence officers are indicted for allegedly penetrating and ransacking Democratic National Committee computer networks during the 2016 campaign.

Aug. 21, 2018: A federal jury in Virginia convicts Manafort of eight counts of tax evasion and bank fraud. On the same day in New York, Cohen pleads guilty to several charges, including campaign finance violations for arranging hush-money payments to two women who said they had sexual affairs with Trump. Cohen told the court that Trump directed the scheme, directly implicating the president in a felony.

Sept. 14, 2018: Manafort pleads guilty to two conspiracy charges to avoid a second federal trial in Washington on more charges related to his work in Ukraine. He agrees to cooperate with the special counsel's office.

Nov. 20, 2018: The president's legal team says it has submitted written answers to questions from Mueller.

Nov. 29, 2018: Cohen pleads guilty for a second time, confessing that he lied to Congress about pursuing a potentially lucrative Trump Tower deal in Moscow on Trump's behalf during the 2016 campaign.

Jan. 25, 2019: Longtime Trump political adviser Roger Stone is arrested at his Florida home and indicted for allegedly lying to the House Intelligence Committee.

March 22, 2019: Mueller files his report.

Los Angeles Times