Ex-F.B.I. Official Is Said to Undercut Justice Dept. Effort to Drop Flynn Case

WASHINGTON — A key former F.B.I. official cast doubt on the Justice Department’s case for dropping a criminal charge against President Trump’s former national security adviser Michael T. Flynn during an interview with investigators last week, according to people familiar with the investigation. Department officials reviewing the Flynn case interviewed Bill Priestap, the former head of F.B.I. counterintelligence, two days before making their…