Inspector General Michael Horowitz's testimony before the Senate Judiciary Committee comes two days after the release of a report that identified significant problems in the Russia probe.
The Russia probe report found no evidence of political bias, despite performance failures, per a summary obtained by The Associated Press.
During the 2016 presidential campaign, Trump campaign chairman Paul Manafort pushed the idea that Ukraine, not Russia, was behind the hack of the Democratic National Committee servers, Manafort's deputy told investigators during the special counsel's Russia probe.
A judge on Friday ordered the Justice Department to give the House secret grand jury testimony from special counsel Robert Mueller's Russia investigation, handing a victory to Democrats who want it for the impeachment inquiry against President Donald Trump.
Investigating the investigators, the Justice Department has shifted its scrutiny of the government's Trump-Russia review to a criminal probe, a person familiar with the matter says. It's raising Democrats' concerns that President Donald Trump may be using federal muscle to go after his opponents.
Lawyers for House Democrats are urging a judge to release secret grand jury testimony from special counsel Robert Mueller's investigation as Congress conducts an impeachment inquiry into President Donald Trump.