In recent days, Justice Department lawyers have asked U.S. District Judge Beryl A. Howell to hold Trump’s office in contempt, according to the people, who spoke on the condition of anonymity to describe sealed court proceedings. Trump is under investigation for three potential crimes: mishandling classified documents, obstruction and destruction of government records. People familiar with those searches by a private firm say no classified documents were found at those locations. It is not uncommon for large organizations to designate a records custodian who can take formal legal responsibility for the company or entity’s files. In recent weeks, a number of Trump advisers have appeared in front of a grand jury hearing evidence in the classified documents case.