A federal judge ruled on Friday that prosecutors overseeing the investigation into former President Donald J. Trump’s handling of classified documents can pierce assertions of attorney-client privilege and compel one of his lawyers to answer more questions before a grand jury, two people familiar with the matter said.
In making her ruling, the judge, Beryl A. Howell, found that the government had met the threshold for the so-called crime-fraud exception, which allows prosecutors to work around attorney-client privilege when they have reason to believe that legal advice or legal services have been used in furthering a crime.
The New York Times reported last month that the office of the special counsel, Jack Smith, had asked Judge Howell to apply the crime-fraud exception to the grand jury testimony of M. Evan Corcoran, a lawyer who has represented Mr. Trump since last spring, as the documents investigation began heating up. Mr. Corcoran appeared before the grand jury in February and asserted attorney-client privilege while declining to answer certain questions.
Judge Howell’s ruling, in a sealed proceeding, that the crime-fraud exception applies in this situation is important because it places the imprimatur of a federal judge on Mr. Smith’s contention that Mr. Corcoran’s legal work may have been used in the commission of a crime.
Among the subjects that the Justice Department has been examining since last year is whether Mr. Trump or his associates obstructed justice by failing to comply with repeated demands to return a trove of government material he took with him from the White House upon leaving office, including hundreds of documents with classified markings.
Last May, before Mr. Smith took over the investigation, federal prosecutors issued a subpoena for any classified documents still in Mr. Trump’s possession — a move taken after the former president had handed over an initial batch of records to the National Archives that turned out to include almost 200 classified documents.
In response to the subpoena, Mr. Corcoran met with federal investigators and gave them another batch of documents, more than 30, with classification markings. He then drafted a statement for another lawyer to give the Justice Department saying that a “diligent search” had been conducted at Mar-a-Lago, Mr. Trump’s club and residence in Florida, and that no more classified materials remained there.
