More: The new case represents another twist in the department's tortured efforts to satisfy the demands of Mr. Trump to pursue criminal charges against Mr. Comey, a longtime target of the president's wrath. The first indictment against Mr. Comey was thrown out by a judge.

The charge stems from an incident nearly a year ago, when Mr. Comey, vacationing on the North Carolina coast, posted a photograph on social media showing seashells arranged to say "86 47," combining the slang term "86" often used to mean dismiss or remove in reference to Mr. Trump, the country's 47th president.