On the night of 18 July 1969, Mary Jo Kopechne died when the car in which she was riding plunged off a low bridge on the Massachusetts island of Chappaquiddick and landed on its roof in the water below. Senator Edward M. Kennedy reported to local police the following morning that he had been driving the car at the time of the accident.

Charged with leaving the scene of an accident, he pleaded guilty and was given a suspended sentence. A coroner’s inquest into Kopechne’s death held in January 1970 and a subsequent grand jury investigation held in March of that year produced no new legal developments.

The last official result of the case was the revocation of Kennedy’s driver’s license in May 1970 after a routine fatal-accident investigation by the Registry of Motor Vehicles. The hearing examiner, like the judge who had sentenced Kennedy, concluded that he had been driving too fast.

Kennedy made no public statement until the week following the accident, when he spoke in a live television broadcast from his home. He stated in that broadcast, and has maintained ever since, that he was driving (but not intoxicated) on the night of the accident and that after the car went into the water he made vigorous (but unsuccessful) efforts to rescue Kopechne.

All conspiracy theories about the accident reject this version of events. The theories fall into three groups that allege, respectively, a conspiracy to place blame on Kennedy, a conspiracy to divert blame from Kennedy, and a conspiracy to cover up an earlier crime by staging the “accident.”

The Setting and the Accident

The island of Martha’s Vineyard lies seven miles off the southeastern coast of Massachusetts. It is divided into six towns, of which Edgartown (at the far eastern end of the island) is the oldest, largest, and most visibly prosperous. Chappaquiddick, where the accident took place, is a political and cultural appendage of Edgartown.

Functionally an island itself, it is separated from Edgartown proper by a 500-foot-wide channel crossed by a small, bargelike car ferry. The eastern edge of Chappaquiddick is a long, straight ocean beach backed by a narrow body of water known as Poucha Pond.

Dyke Bridge, the site of the accident, arches over the pond, connecting Chappaquiddick’s small road system to the parking lot behind the beach. The bridge (since demolished and rebuilt) angled 27 degrees to the left of the road leading to it. It had, in 1969, only 4-inch strips of timber to mark the edges of its deck.

Kennedy and Kopechne—a former member of Senator Robert F. Kennedy’s staff—arrived separately at a party held at a rented cottage on Chappaquiddick on the night of 18 July. Leaving the cottage together shortly before 12:45 A.M., they drove north in a black 1967 Oldsmobile 88 toward Chappaquiddick’s main intersection. A left turn at the intersection, following Chappaquiddick’s sole paved road, would have taken them to the ferry landing— their intended destination, according to Kennedy.

Instead, upon reaching the intersection, they turned right onto the gravel road leading to Dyke Bridge and the beach beyond. Deputy Sheriff Christopher Look, a Chappaquiddick resident on his way home, reached the intersection at the same time and witnessed the turn. Moments later, the car carrying Kennedy and Kopechne reached the bridge and failed to negotiate it.

Traveling at 20–25 miles per hour, it jumped the low guard rails and ran off the right side of the bridge, hitting the water on its right side and rolling inverted as it sank into 8–10 feet of water. Kennedy, apparently washed out of the car by the in-rushing water, escaped. Kopechne, trapped as the car rolled over, drowned.

Conspiracy to Blame Kennedy

Heir to the greatest political dynasty in twentieth-century U.S. history, Edward Kennedy was considered a strong contender for the Democratic presidential nomination in 1972. The accident effectively ended his chances of winning the nomination, and he announced in 1970 that he would not run. Conspiracy theorists of the political Left speculated, as a result, that the “accident” had been staged by agents of the Right to achieve precisely that goal.

Kennedy, according to this theory, was kidnapped, drugged, placed in the car with Kopechne, and pushed off the bridge—leaving him (if he survived) to explain why he was headed for a deserted beach at midnight with a woman who was not his wife.

Allegations of rightwing involvement in the assassinations of President John F. Kennedy in 1963 and leading presidential candidate Robert F. Kennedy in 1968 lent a measure of plausibility to such theories. So, after 1973, did revelations that the Nixon administration had employed “dirty tricks,” some of them illegal, against its political enemies.

Few believers in a right-wing framing of Kennedy have developed the theory in depth. The principal exception is R. B. Cutler, 1973 whose self-published book You, The Jury outlines a complex scenario involving three separate groups of agents and a Kennedy look-alike used as a temporary decoy.

Cutler’s book blames the framing on unspecified individuals or organizations determined to bar Kennedy from the presidency. Richard Nixon, his aides, and his sympathizers are never named as coconspirators, but readers are left free to infer their involvement.

The limited popularity of frame-up theories about the accident is due in part to their fundamental implausibility. Why, critics reasonably ask, would Kennedy not protest that he was being framed? Why would he plead guilty before a local judge the week after the accident?

Why would he publicly admit guilt in his televised speech later the same day? Why, in other words, would Kennedy do the conspirators’ work for them by confessing to a reputation-damaging act that he knew he did not commit?

Conspiracy to Shield Kennedy

The most widely held conspiracy theories about the accident propose that Kennedy conspired with others to cover up the true extent of his guilt. Their popularity reflects the widespread sentiment that the wealthy, the powerful, and the well-connected can easily escape punishment for their crimes. The Kennedy family possessed wealth, power, and connections in abundance, and their willingness to use all three to their advantage is well established.

The perceived incongruity of crime and punishment in the Chappaquiddick case—a two-month suspended sentence for acts resulting in the death of a young woman—led many to conclude that wealth and privilege had triumphed again. These perceptions ran especially strong among longtime residents of Martha’s Vineyard, fueled by suspicion of wealthy, privileged vacationers from the mainland.

One variation of this theory has Kennedy conspiring with associates to craft an “official” story about the accident that would minimize his guilt. Washington Post columnist Jack Anderson suggested in 1969, for example, that Kennedy asked Joseph Gargan and Hugh Markham—two longtime associates who were also at the party—to lie to police and say that Gargan or Kopechne herself had been at the wheel of the car. Leo Damore gave the theory new life in his 1988 book Senatorial Privilege.

Many residents of Martha’s Vineyard see evidence of a similar conspiracy in Kennedy’s claims that he turned toward the bridge without realizing it, dived on the wreck in an effort to save Kopechne, and later swam the channel separating Chappaquiddick from Edgartown.

They believe that the claims are patently absurd—a heroic fiction created by Kennedy and others to cover an uglier reality in which Kennedy, drunk, fled the scene of the accident and used his connections to slip back quietly to his Edgartown hotel without rousing the ferryman and attracting attention.

A second variation of the theory suggests that the Kennedy family used their wealth, power, or political connections to subvert, divert, or obstruct official investigations of the accident.

Commentators who believe in such a conspiracy argue that the postaccident investigations were inadequate at best and negligent at worst—failings best explained not by disinterest but by active tampering. Why, they ask, did the Edgartown police not thoroughly search the area around the accident scene for telltale physical evidence?

Why did the state police lieutenant who headed the investigation for the Commonwealth of Massachusetts fail to question key witnesses and discourage the district attorney from ordering an autopsy? Why did the judge in charge of the grand jury investigation set the ground rules in such ways that virtually guaranteed it would be ineffective?

The slipshod investigation and prosecution were, they argue, orchestrated by Kennedy and others in a series of phone calls made in the time between the accident and the first report of it to the police. The extent of the family’s power over Massachusetts politics made it possible for them to quickly and efficiently subvert the criminal justice system.

Theories about conspiracies to conceal the nature of Kennedy’s offense and deflect the full force of the law from him are the least spectacular of the three types. They are also the most plausible: the investigation was, in retrospect, seriously flawed.

Conspiracy-theory critics such as James Lange and Katherine DeWitt have noted, however, that the flaws are not in themselves proof of conspiracy. They can be explained equally well by more mundane causes: incompetence, laziness, the distraction of more pressing cases, or the biases of particular individuals.

Conspiracy to Stage the Incident

The third type of conspiracy theory combines elements of the first two types. Like the first type of theory, it proposes that the accident was staged; like the second, it accuses Kennedy of conspiring to cover up the true extent of his guilt. Specifically, the third type of theory suggests that Kennedy and several close friends engineered the “accident” in order to cover up other misdeeds.

Kenneth Kappel, in his 1989 book Chappaquiddick Revealed, begins with the premise that Kennedy must have been drunk by the time he and Kopechne got into the car. He suggests that an alcohol-impaired Kennedy ran the car off the road (not the bridge), causing it to roll over, leaving Kennedy hurt and Kopechne unconscious.

Kennedy and several friends, believing that Kopechne was already dead, righted the car and pushed it off the bridge into the pond in order to hide the evidence long enough for Kennedy to sober up. Kopechne regained consciousness after the car hit the pond and, unable to escape, drowned. Kappel’s theory thus has Kennedy and his coconspirators unintentionally committing manslaughter in the process of trying to hide the much less (legally) serious crime of drunken driving.

A second variation of this theory takes it significantly further, positing that Kennedy murdered Kopechne and then drove (or pushed) the car off the bridge to conceal the fact. Many commentators on the accident assume that (despite his denials) Kennedy had or sought sex with Kopechne.

Adherents of the murder-cover-up theory frequently expand that assumption into the speculation that the couple had a prior sexual encounter that left Kopechne pregnant. Pregnancy would, the adherents argue, provide Kennedy with a motive for the alleged murder and cover-up. Zad Rust’s 1971 book Teddy Bare strongly implies—but, presumably to avoid a libel suit, does not explicitly claim—both pregnancy and murder, covered up by a staged accident.

Neither Kappell, nor Rust, nor any of the less prominent advocates of such theories can adequately account for how Kennedy and a few friends could push the car into the water. The bridge’s 4-inch-high rails—though no barrier to a vehicle driven at 20 miles per hour—would be a substantial obstacle to a 2-ton vehicle being pushed uphill by three or four men struggling to find purchase on a dirt-and-gravel road in casual shoes.

Nor can such theories account for the dark tire marks that law enforcement officers observed on the bridge deck the morning after the accident. The marks suggest a car skidding with locked brakes—an image fully compatible with an accident, but virtually impossible to stage on the spur of the moment.

Allegations that Kopechne was strangled to death are equally difficult to reconcile with the failure of the local medical examiner to find any marks on her throat when he examined her body the morning after the accident. Allegations that she was pregnant by Kennedy are equally dubious, and equally inconsistent with established facts.