You're reading: Bloomberg: Mueller digs in on expanding Russia probe as Trump attacks FBI

Special Counsel Robert Mueller’s investigation into Russian meddling in the U.S. election is entering a new phase, with a newly cooperating star witness and hints that he may be pursuing a more serious case against President Donald Trump.

Trump’s former national security adviser, Michael Flynn, pleaded guilty December 1 to lying to FBI agents, becoming the fourth associate of the president ensnared by Mueller’s probe. More significantly, he also is providing details to Mueller about the Trump campaign’s approach to Flynn’s controversial meeting with a Russian envoy during the presidential transition.

Read more here.