WASHINGTON (AP) — Former special counsel Robert Mueller has finished testifying before Congress.

Mueller testified before two committees on Wednesday for more than six hours on his 448-page report on Russian interference in the 2016 election.

Mueller said the interference was not a hoax, and it was not an isolated episode.

He warned that there should be a more robust effort to guard against future interference.

House intelligence committee Chairman Adam Schiff said the Democratic investigations will continue.

Mueller answered most questions in short sentences, referring Congress members to his report and choosing not to read his report aloud.

Mueller had made clear in his report that he could not exonerate President Donald Trump on obstruction of justice in the probe.

But investigators didn’t find sufficient evidence to establish charges of criminal conspiracy between the Trump campaign and Russia.