Adams Leads in N.Y.C. Mayoral Primary, but Ranked-Choice Awaits

Voters on Tuesday took part in the city’s first mayoral election using ranked-choice voting, a system that may delay the declaration of a winner until mid-July.

Eric Adams, who ran for mayor of New York City on a message intensely focused on issues of public safety, emerged on Tuesday with a substantial lead in the Democratic primary, but fell well short of outright victory in a race that will now usher in a new period of uncertainty.

With 82 percent of the results in, Mr. Adams, the Brooklyn borough president,...