Despite the mayor's plan to drop the city's appeal, police unions are now challenging a judge's decision that called for reforms to the New York City Police Department's stop-and-frisk policy.
The unions are asking for courts to decide if U.S. District Court Judge Shira Scheindlin acted properly last summer when she ruled that stop-and-frisk is sometimes discriminatory.
She also ordered changes to the department-wide practice, including the appointment of an independent monitor.
Scheindlin had been removed from the case because a higher court ruled that she misapplied a related ruling and spoke publicly about it.
Former Mayor Michael Bloomberg filed an appeal of her decision last year, but last month, Mayor Bill de Blasio announced that the city would drop that appeal and appoint a monitor.