WASHINGTON — Attorney General Merrick Garland on Thursday appointed a special counsel to investigate the presence of documents with classified markings found at President Joe Biden's home in Wilmington, Delaware, and at an office in Washington.

The announcement followed Biden's acknowledgment Thursday morning that a document with classified markings from his time as vice president was found in his personal library, along with other classified documents found in his garage. Garland said Biden's lawyers informed the Justice Department Thursday morning of the discovery of a classified document at Biden's home, after FBI agents first retrieved other documents from the garage in December. It was disclosed on Monday that sensitive documents were found at the office of his former institute in Washington.

Robert Hur, the former Trump-appointed U.S. attorney in Maryland, will lead the investigation, taking over from the top Justice Department prosecutor in Chicago, John Lausch, who was earlier assigned by the department to investigate the matter and who recommended to Garland last week that a special counsel be appointed. Hur is to begin his work soon.

“The extraordinary circumstances here require the appointment of a special counsel for this matter,” Garland said, adding that Hur is authorized to investigate whether any person or entity violated the law.

“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,” Garland said.

Biden told reporters at the White House that he was “cooperating fully and completely” with a Justice Department investigation into how classified information and government records were stored.

“We have cooperated closely with the Justice Department throughout its review, and we will continue that cooperation with the special counsel,” said Richard Sauber, himself a special counsel to the president. “We are confident that a thorough review will show that these documents were inadvertently misplaced, and the president and his lawyers acted promptly upon discovery of this mistake.”

Biden's lawyers found the first set of documents in a locked closet in the offices of the Biden Penn Center in Washington on Nov. 2, just before the midterm elections, but publicly revealed that development only on Monday.

Sauber said that after Biden's personal lawyers found the initial documents, they examined other locations where records might have been shipped after Biden left the vice presidency in 2017.

Biden did not say when the latest documents were found at his home, only that his lawyers' review of potential storage locations was completed Wednesday night.

Sauber said a “small number” with classified markings were found in a storage space in Biden's garage in Wilmington, with one document being located in an adjacent room. Biden later revealed that the other location was his personal library.

Garland said Biden attorneys located documents in the Wilmington garage on Dec. 20 and that Federal Bureau of Investigation agents took custody of them shortly thereafter. The Justice Department was informed only on Thursday of the latest found by Biden's lawyers.

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.

“I will conduct the assigned investigation with fair, impartial and dispassionate judgment,” he said in a statement after his appointment. “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.”

New House Speaker Kevin McCarthy, a California Republican, said of the latest news: “I think Congress has to investigate this.”

“Here's an individual that sat on '60 Minutes' that was so concerned about President Trump's documents locked in behind, and now we find that this is a vice president keeping it for years out in the open in different locations.”

Contradicting several fellow Republicans, he said, “We don't think there needs to be a special prosecutor.”

The top Republican on the House Intelligence Committee has requested that intelligence agencies conduct a “damage assessment” of potentially classified documents. Ohio Rep. Mike Turner on Thursday also requested briefings from Garland and the director of national intelligence, Avril Haines, on their reviews by Jan. 26.

“The presence of classified information at these separate locations could implicate the President in the mishandling, potential misuse, and exposure of classified information,” Turner wrote the officials.

The revelation that additional classified documents were uncovered by Biden's team came hours after White House press secretary Karine Jean-Pierre dodged questions about Biden's handling of classified information and the West Wing's management of the discovery.

She had said Wednesday that the White House was committed to handling the matter in the “right way,” pointing to Biden's personal attorneys' immediate notification of the National Archives.

But she refused to say when Biden himself had been briefed, whether there were any more classified documents potentially located at other unauthorized locations, and why the White House waited more than two months to reveal the discovery of the initial batch of documents.

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.