Who is Robert Mueller, special counsel overseeing Russia investigation?

Former FBI Director Robert Mueller arrives to testify before the House Judiciary Committee in 2013. The Justice Department announced Wednesday that Mueller will lead the FBI's investigation into Russia's meddling in the 2016 election.
Former FBI Director Robert Mueller arrives to testify before the House Judiciary Committee in 2013. The Justice Department announced Wednesday that Mueller will lead the FBI's investigation into Russia's meddling in the 2016 election.