AMERICANS EITHER LOVE the Fifth Amendment of hate it. Best known and most lovingly hated for its other clauses, the Fifth's first guarantee is that "No person shall be held for a capital, or otherwise infamous crime, unless on a presentment or indictment by a Grand Jury." Transplanted from England, where it began life as a body of local snitches for the King, the grand jury was perceived by our Founding Fathers as having two quite different purposes. As everyone who has read about John Peter Zenger's case knows, it could be a shield for the individual against overreaching prosecutors. And as everyone (which is everyone) who has read about the work of the Watergate grand jury knows, it could serve as a people's watchdog for governmental corruption and criminality.

Enlightened as the Founding Fathers' plans for it were, the grand jury has not been the object of uniform admiration. Laden with large and secret powers, too often of late ot has seemed to be the tool of rampaging prosecutors of the sort who believe, or who believe it may be popular to believe, that the Joseph R. McCathys, the John Mitchells, and the Anita Bryants are repositories of a nation's conscience. It has been used to harrass the unorthodox and, as the authors of the Grand Jury: An Institution on Trial eloquently put it, "There has been badgered, trapped, subjected to harsh, sudden and wearing appearances in distant places, defamed by leaks not necessarily accidental, or otherwise scarred by gratuitously high-handed or perverse employment of the grand jury's great authority." Not much wonder then, at that there is a goodly amount of public concern about the uses of the grand jury and even a body of opinion which favors outright elimination of the insitution.

If only because obolition of the grand jury would work the first change ever made in any part of th Bill of Rights and perhaps make more consequential tinkering too easy, there is need for a calm and careful study of the issues and the options. Fortunately for the people and their representatives, this book fills that need.

There have been other books about the grand jury, long scholarly things, freighted with footnotes, by authors who had never seen the inside of a grand jury room. What has been wanted,and what until now we have lacked, is an analysis by responsible commentators who understand not only the grand jury's checkered history, which does not have much current value except in the construction of rhetoric, but also how the mechanism is actually operating today. From day-in, day-out experience Marvin Frankel, one of the country's most effective federal trial judges, and Gary Naftsalis. a former federal prosecutor of the sort whose appointment gave meaning to the term "merit selection," know what they are talking about. They supply a touch of history, just enough to impart flavor. (There are after all too many deliciously gruesome accounts of the four species of trial by ordeal - cold water, hot water, hot iron, and "the morsel" - to pass them up altogether.) This is followed by fascinating behind-the-court-house-scenes description of how the different types of federal grand juries function. Then the authors present their assessment of every current proposal that in any important way touches the grand jury's fate.

Judge Frankel and Naftalis conclude " that the heavy burden of justifying an amendment to eliminate the grand jury passes from the scene, its investigative and indicting functions will only be lodged elsewhere and the case is yet to be made that alternative mechanisms are certain to be improvements.

On the other hand, the grand jury, if it is to remain vital and worthy, plainly needs improvement. Frankel and Naftalais review the catalog of pending proposals, beginning with legislation that would require judges more effectively to advise new grand jurors of their broad authority. The authors think this a good suggestion; one of them, surely the senior author, adds that. "It would certainly be supposed that the improvement will be attempted, without further prompting, by judges who help to write books about grand juries."

Next taken up are proposals that grand jury proceedings should almost invariably be transcribed (the authors approve); that a witness should be permitted to have a legal adviser with him in the grand jury room (approved); that decent notice be accorded witnesses and that they ordinarily should not be required to travel great distances to give their testimony (approved); that witnesses should be informed of their rights (approved); that they should be entitled to have a free transcript of their own testimony (approved); that a prospective defendants, even though not summoned by the grand jury, should be allowed to appear voluntarily to present his side of the matter (approved); that prosecutors be required to present evidence favourable to the prospective defendant (disapproved); that ther be a flat prohibition against repetitive efforts to indict (disapproved); that prosecutors be barred from engaging in press conferences and "other celebrations" to mark the issuance of indictments "vigorously approved); that independent "Watergate" grand juries be forbidden to issue broad-ranging reports (disapprovced, but the authors suggest some sensible limitations on their subject matter); and that there be significang sanctions against the leaking of grand jury activities (largely approved).

All of this, and a good bit more, is presented in a vocabulary wuich emphasizes the authors' knowledge and their rationality rather than some strained sense of literary style. The product,rare from the pens of lawyers, is a book of crystalline clarity. It sets up a model, not just for those who want to rewrite the rul es for grand juries, but for anyone who hopes to write comprehensible about other important and complicated subjects.