Democratic New York Rep. Jerry Nadler issued a subpoena Monday that orders former White House counsel Donald McGahn to testify before the House Judiciary Committee over documents related to charges that President Donald Trump obstructed justice.

“The special counsel’s report, even in redacted form, outlines substantial evidence that President Trump engaged in obstruction and other abuses,” Nadler said in a statement, calling McGahn “a critical witness to many of the allege instances of obstruction of justice and other misconduct described in the Mueller report.”

Nadler added: “His testimony will help shed further light on the president’s attacks on the rule of law, and his attempts to cover up those actions by lying to the American people and requesting others do the same.” McGahn is the first former White House employee to be subpoenaed after the Justice Department published special counsel Robert Mueller’s report into Russian intervention.

Nadler, who chairs the committee, also issued a subpoena for Mueller’s report, absent redactions.

Mueller was unable to establish that the Trump campaign conspired or colluded with the Russian government to influence the 2016 election. He also declined to issue additional indictments prior to ending his nearly two-year long investigation. Mueller obtained thirty-four indictments or guilty pleas during the 22-month probe, but none for election-related conspiracies involving Trump associates.