BALTIMORE — A judge aggressively questioned prosecutors Thursday about why they charged an officer with assault in the arrest of Freddie Gray, and asked whether every officer who makes an arrest without probable cause should be charged with a crime.

Baltimore Circuit Judge Barry Williams grilled prosecutors during their closing arguments in the bench trial of Officer Edward Nero, who was one of three officers who chased Gray when he ran after making eye contact with an officer. Once Gray was in custody, officers found a knife on him, but the judge previously ruled that the knife's legality wouldn't be part of the trial.