The U.S. Justice Department asked a federal judge to appoint an independent monitor to oversee the New York Police Department if she rules the department's stop-and-frisk policy is unconstitutional.

U.S. District Judge Shira Scheindlin presided at a 10-week civil trial over the New York police practice of stopping people suspected of unlawful activity and frisking those suspected of carrying weapons.

Critics of the policy say it targets minorities and violates their Fourth Amendment rights for protection against unreasonable searches and seizures.