By MATT BROWN

WASHINGTON (AP) — A former senior aide to Jill Biden on Wednesday became the second person to invoke the Fifth Amendment and decline to answer questions from House Republicans who are investigating President Joe Biden’s mental state and use of the autopen while in office.

Anthony Bernal, who previously served as chief of staff to former first lady Jill Biden, was subpoenaed for his testimony by the House Oversight Committee. He declined to answer questions, invoking the protections that prevent people from being forced to testify against themselves in government proceedings.

“Well, unfortunately, that was quick,” said Rep. James Comer, chair of the House Oversight Committee, after the deposition ended. “I believe the American people are concerned. They’re concerned that there were people making decisions in the White House that were not only unelected but no one to this day knows who they were.”

Bernal ignored questions from reporters as he entered and exited the House Oversight Committee’s hearing room on Capitol Hill. He was accompanied by his lawyer, Jonathan Su, who was a deputy White House counsel to the former president. Su in a statement provided to the committee noted that pleading the Fifth is not evidence of wrongdoing.

The former president has dismissed the inquiries as legally spurious. In a recent interview with the New York Times, Biden said that he delegated responsibilities when necessary as president but was actively involved and knowledgeable of all of his administration’s actions, including on granting clemency.

“I consciously made all those decisions,” Biden said.

Comer has sought testimony from nearly a dozen former Biden aides as he conducts his investigation, including former White House chiefs of staff Ron Klain and Jeff Zients; former senior advisers Mike Donilon and Anita Dunn; former deputy chief of staff Bruce Reed, former counselor to the president Steve Ricchetti, former deputy chief of staff Annie Tomasini and a former assistant to the president, Ashley Williams.

On Tuesday, Comer also subpoenaed Annie Tomasini, a former White House deputy chief of staff, to appear before the committee on July 18. She is the third former official to be subpoenaed by the committee.

Democrats have been dismissive of the Republican probe as mere political theater.

“They still look like losers,” said Rep. Jasmine Crockett, D-Texas, who sat in on Bernal’s committee deposition.

But many Republicans see the investigation as a top priority for their caucus and a politically salient issue for voters ahead of the midterm election. The Trump White House has launched its own probe into Biden’s age while Senate Republicans have also held hearings on the topic.

“This is corruption at the highest level, because if you cannot answer a simple question about Joe Biden’s capabilities, then that further demonstrates that he was not in charge of his administration,” said Rep. Byron Donalds, R-Fla., who sat in on Bernal’s deposition.

Donalds said “every member of the Biden administration, at this point, needs to be subpoenaed,” including Vice President Kamala Harris and Jill Biden.

Comer did not rule out seeking testimony from Harris or members of Biden’s family.

“We’re going to bring in everyone. We’re moving up the line,” Comer said. “We’ve started with the lower level staffers that we think were the ones that actually put the documents in the autopen and pressed power. Now we’re moving up to the people that we think told the staffers to use the autopen.”

“So we’ll we’ll see where that takes us,” Comer said. “But I think the possibility is very good that we’ll be asking members of the family to come in.”

Associated Press writer Michelle L. Price contributed reporting.