On the other hand, grand juries do occasionally refuse to return indictments. In 1984, Bernard Goetz shot four teenagers on the New York City subway, allegedly in self-defense. The first grand jury that heard the case refused to indict him for attempted murder. New York’s district attorney, Robert Morgenthau, citing additional evidence, brought the case before the grand jury a second time (the double jeopardy clause of the 5th Amendment does not apply to grand juries). The second grand jury returned an indictment. But at his criminal trial, Goetz was found not guilty, which was something of a vindication for the first grand jury.
Unlike most of the guarantees in the Bill of Rights, the grand jury requirement has never been incorporated against the states. In 2012 there was controversy when a Florida prosecutor filed charges against George Zimmerman in the shooting death of Trayvon Martin without seeking a grand jury indictment. But states have differing rules about grand juries, and the state of Florida requires them only in capital crimes.
But even if the grand jury is rarely called upon to fulfill one of its original purposes (as described by Justice Story) of protecting “citizens against vindictive prosecutions,” it still performs another important function. An indictment clarifies the particulars of the accusation, “so that the party may have full notice of the charge, and be able to make his defence with all reasonable knowledge and ability.” In the words of Blackstone, the combination of a grand jury indictment and a petit jury trial provides a “strong and twofold barrier . . . between the liberties of the people, and the prerogative of the crown.”