Attorney General Merrick Garland on Thursday announced Robert Hur will serve as special counsel to investigate classified documents found at President Joe Biden’s home and former office from his time as vice president, amid questions about why the White House delayed public announcements of the discovery of the sensitive records.

The news about the special counsel came hours after the White House confirmed President Biden's legal team discovered "a small number" of additional Obama-Biden administration documents at his house in Wilmington, Delaware, in December and just days after an attorney for the president said Biden's lawyers in early November had discovered classified records at his former office space in Washington.

Neither discovery was confirmed by the White House until this week – and only after media reports first revealed them.

Details in Garland's announcement threw into question the White House's claims of transparency.

For the second day in a row, press secretary Karine Jean-Pierre refused to answer specific questions about the documents, including where exactly they were found in Biden's home and at what point they were turned over to the Justice Department.

"There's an ongoing process," she said repeatedly, in part to explain why news of the documents wasn't made public sooner.

On Thursday morning, special counsel to the president Richard Sauber had confirmed that a second set of classified records were found in Wilmington, one day after NBC News first reported the fact.

But that statement did not reveal that the records were found in December, a fact that Garland later shared. One document was found Wednesday evening as the search for additional files wrapped up.

Jean-Pierre could not fully answer why the White House did not publish information about the December documents earlier this week, when the first batch became news.

"We have been transparent here. That is why the minute that his lawyers found those documents, they recorded it, they reached out to the [National] Archives and the Department of Justice, and they did that voluntarily," she said.

In a statement, Sauber pledged to cooperate with the special counsel and said that they are "confident" the probe will show that the documents "were inadvertently misplaced." 

He added: "We have cooperated closely with the Justice Department throughout its review, and we will continue that cooperation with the Special Counsel."

Garland on Thursday said that an initial review from John R. Lausch Jr., the U.S. attorney for the Northern District of Illinois, found that “further investigation by a special counsel was warranted.” 

“Based on Mr. Lausch’s initial investigation, I concluded that under the Special Counsel regulations, it was in the public interest to appoint a special counsel,” Garland said Thursday. “In the days since, while Mr. Lausch continued the investigation, the department identified Mr. Hur for appointment of Special Counsel.” 

“This appointment underscores for the public the department's commitment to both independence and accountability in particularly sensitive matters, and to making decisions indisputably guided only by the facts and the law,” he continued. “I am confident that Mr. Hur will carry out his responsibility in an even-handed and urgent manner and in accordance with the highest traditions of this department.”

Hur, the former Trump-appointed U.S. attorney in Maryland, is to begin his work soon.

Hur was a close ally of former Deputy Attorney General Rod Rosenstein, a key figure in special counsel Robert Mueller's investigation into Russian interference in the 2016 U.S. election and contacts between then-candidate Trump's associates and Russian officials. He also worked as an adviser to FBI Director Christopher Wray in the Justice Department.

"I will conduct the assigned investigation with fair, impartial, and dispassionate judgment," Hur said in a statement following the announcement. "I intend to follow the facts swiftly and thoroughly, without fear or favor, and will honor the trust placed in me to perform this service."

The appointment of yet another special counsel to investigate the handling of classified documents is a remarkable turn of events, legally and politically, for a Justice Department that has spent months looking into the retention by Donald Trump of more than 300 documents with classification markings found at the former president’s Florida estate.

Though the situations are factually and legally different, the discovery of classified documents at two separate locations tied to Biden — as well as the appointment of a new special counsel — would almost certainly complicate any prosecution that the department might bring against Trump.

Earlier this week, the White House first confirmed that the Department of Justice was reviewing "a small number of documents with classified markings" found at the office. Biden's attorneys had discovered the documents at the offices of the Penn Biden Center and then immediately called the National Archives about the discovery, the White House said. Biden kept an office there after he left the vice presidency in 2017 until shortly before he launched his Democratic presidential campaign in 2019.

But the White House did not acknowledge the second set of documents until Wednesday media reports.

Sauber said in a statement Thursday that Biden's attorneys searched Wilmington and Rehoboth Beach, Delaware, residences, in coordination with the Department of Justice.

"During the review, the lawyers discovered among personal and political papers a small number of additional Obama-Biden Administration records with classified markings," Sauber said. "All but one of these documents were found in storage space in the President’s Wilmington residence garage. One document consisting of one page was discovered among stored materials in an adjacent room."

"No documents were found in the Rehoboth Beach residence," Sauber added, before noting that they "immediately notified" the Justice Department to take posession of the documents.

Biden addressed the new revelation at a White House event celebrating the recent inflation and unemployment figures.

"People know I take classified documents and classified material seriously," Biden said. 

"My lawyer has reviewed other places where documents from my time as vice president were stored, and they finished the review last night," Biden continued. "They discovered a small number of documents with classified markings in storage areas and file cabinets in my home, in my personal library."

It was unclear if his personal library was the room "adjacent" to the garage where one record was found, as detailed in the White House statement Thursday. Press secretary Jean-Pierre could not clarify.

"We're going to see all of this unfold, I'm confident," Biden said.

In response to a reporter asking why Biden had documents in his garage next to his Corvette, Biden quipped that the room was locked: "By the way, my Corvette is in a locked garage. Okay? So it's not like you're sitting out on the streets."

Irrespective of the Justice Department review, the revelation that Biden potentially mishandled classified or presidential records could prove to be a political headache for the president, who called Trump's decision to keep hundreds of such records at his private club in Florida "irresponsible."

Biden has said he was "surprised to learn that there are any government records that were taken there to that office" but his lawyers "did what they should have done" when they immediately called the National Archives.

The top Republican on the House Intelligence Committee has requested that the U.S. intelligence community conduct a "damage assessment" of potentially classified documents.

The revelation also may complicate the Justice Department's consideration of whether to bring charges against Trump, a Republican who is trying to win back the White House in 2024 and has repeatedly claimed the department's inquiry into his own conduct amounted to "corruption."

There are significant differences between the Trump and Biden situations, including the gravity of an ongoing grand jury investigation into the Mar-a-Lago matter.