U.S. District Judge Richard Leon, who graduated from Suffolk Law in 1974, has been asked to decide if a former national security official for the Trump administration can legally testify in the impeachment inquiry.

Charles Kupperman, the official in question, was the aide to former National Security Advisor  John Bolton. Kupperman was issued a congressional subpoena to testify, but failed to appear in court on Monday.

He was summoned to court because he was on a July 25 call between President Donald Trump and Ukraine’s president Volodymyr Zelensky. In the call, Trump asked Zelensky to investigate former vice president and presidential candidate Joe Biden and his son Hunter, as well as the 2016 U.S. presidential election.

The White House said Kupperman is entitled to immunity and should not have to testify. Democrats disagreed.

“Charles Kupperman’s failure to appear for his deposition today is potential obstruction of the inquiry and any blocked testimony should be considered corroborative of the whistle-blower’s complaint,” Illinois Congressman Raja Krishnamoorthi, D, wrote on Twitter.

According to House Democrats, the House will vote on Thursday to formalize the impeachment inquiry.