CHAPPAQUIDDICK

Intriguing if not wholly convincing reconsideration of the July 1969 car crash that killed Mary Jo Kopechne and effectively ended Senator Edward Kennedy's presidential aspirations. Lange (an attorney) and DeWitt (a copywriter) begin with perfunctory tabloid-like sketches of Kopechne and the Kennedys that telegraph more of an interest in detective work than in the people involved. We're told that Joseph Kennedy, Jr., ``was the one Mother loved best'' and, half a page later, that Kathleen Kennedy ``was Rose's favorite child.'' Things make more sense as the authors trace the events leading up to the accident; examine testimony on what may have happened afterward; and outline various theories about what actually did happen. The details are endless and the reasoning intricate as the authors find every past theory inadequate to explain certain actions and events. And so Lange and DeWitt offer ``One More Theory'': ``that the senator was largely telling the truth.'' In doing so, they tackle the big mysteries of the case: Kennedy's failure to report the crash for many hours, and his bizarre swim to a neighboring island after the accident. The authors point out that his original statements to police and his later courtroom testimony agree substantively, except about that swim, and they indicate that any discrepancies are due to Kennedy having been ``non compos mentis,'' probably in ``traumatic amnesia'' marked by ``befuddlement'': Although there was, they say, ``no proper medical assessment'' of the senator at the time, witnesses described actions consistent with amnesiac behavior. The research here is remorseless, but the simplistic psychology of the early pages undermines confidence. (Eight pages of photographs, two maps)