More than two dozen Russian nationals and entities have been charged for their alleged efforts to interfere in the 2016 election, and Mueller has indicted individuals with ties to the Trump campaign and administration.
Those swept up in the high-profile investigation range from President Trump’s longtime personal lawyer Michael Cohen to lesser-known figures like Alex van der Zwaan, who pleaded guilty to making false statements to investigators.
Trump has repeatedly attacked the probe as a “witch hunt,” while Mueller has remained tight-lipped throughout, largely choosing to speak by way of court filings and criminal charges.
As the investigation heads into 2019, here is a timeline of the biggest developments.
May 17, 2017: Mueller appointed special counsel
Deputy Attorney General Rod Rosenstein announces Mueller’s appointment to oversee the investigation into Russia’s interference in the 2016 presidential election, a move that comes almost immediately after Trump fires James Comey as FBI director.
June 14, 2017: Possible obstruction of justice