Document Inquiry Poses Unparalleled Test for Justice Dept.

As Justice Department officials haggled for months this year with former President Donald J. Trump’s lawyers and aides over the return of government documents at his Florida home, federal prosecutors became convinced that they were not being told the whole truth.

That conclusion helped set in motion a decision that would amount to an unparalleled test of the Justice Department’s credibility in a deeply polarized political environment: to seek a search warrant to enter Mar-a-Lago and retrieve what prosecutors suspected would be highly classified materials, beyond the hundreds of pages...