Mary Jo Kopechne, the daughter of an insurance salesman, was born in the village of Forty Fort, Pennsylvania, on 26th July 1940. After graduating from Caldwell College for Women in New Jersey, she moved to Washington where she worked as a secretary for George Smathers and Robert Kennedy. During this time she shared an apartment with Nancy Carole Tyler, who worked for Bobby Baker.
On 17th July, 1969, Kopechne joined several other women who had worked for the Kennedy family at the Edgartown Regatta. She stayed at the Katama Shores Motor Inn on the southern tip of Martha's Vineyard. The following day the women travelled across to Chappaquiddick Island. They were joined by Edward Kennedy and that night they held a party at Lawrence Cottage. At the party was Kennedy, Kopechne, Susan Tannenbaum, Maryellen Lyons, Ann Lyons, Rosemary Keough, Esther Newburgh, Joe Gargan, Paul Markham, Charles Tretter, Raymond La Rosa and John Crimmins.
Kopechne and Edward Kennedy left the party at 11.15pm. Kennedy had offered to take Kopechne back to her hotel. He later explained what happened: "I was unfamiliar with the road and turned onto Dyke Road instead of bearing left on Main Street. After proceeding for approximately a half mile on Dyke Road I descended a hill and came upon a narrow bridge. The car went off the side of the bridge.... The car turned over and sank into the water and landed with the roof resting on the bottom. I attempted to open the door and window of the car but have no recollection of how I got out of the car. I came to the surface and then repeatedly dove down to the car in an attempt to see if the passenger was still in the car. I was unsuccessful in the attempt."
Instead of reporting the accident Edward Kennedy returned to the party. According to a statement issued by Kennedy on 25th July, 1969: "instead of looking directly for a telephone number after lying exhausted in the grass for an undetermined time, walked back to the cottage where the party was being held and requested the help of two friends, my cousin Joseph Gargan and Paul Markham, and directed them to return immediately to the scene with me - this was some time after midnight - in order to undertake a new effort to dive."
When this effort to rescue Kopechne ended in failure, Kennedy decided to return to his hotel. As the ferry had shut down for the night Kennedy, swam back to Edgartown. It was not until the following morning that Kennedy reported the accident to the police. By this time the police had found Mary Jo Kopechne's body in Kennedy's car.
Edward Kennedy was found guilty of leaving the scene of the accident and received a suspended two-month jail term and one-year driving ban. That night he appeared on television to explain what had happened. He explained: "My conduct and conversations during the next several hours to the extent that I can remember them make no sense to me at all. Although my doctors informed me that I suffered a cerebral concussion as well as shock, I do not seek to escape responsibility for my actions by placing the blame either on the physical, emotional trauma brought on by the accident or on anyone else. I regard as indefensible the fact that I did not report the accident to the police immediately."
At the inquest Judge James Boyle raised doubts about Kennedy's testimony. He pointed out that as Kennedy had a good knowledge of Chappaquiddick Island he could not understand how he managed to drive down Dyke Road by mistake. For example, on the day of the accident, Kennedy had twice had driven on Dyke Road to go to the beach for a swim. To get to Dyke Road involved a 90-degree turn off a metalled road onto the rough, bumpy dirt-track.
An investigation at the scene of the accident by Raymond R. McHenry, suggested that Kennedy approached the bridge at an estimated 34 miles (55 kilometres) per hour. At around 5 metres (17 feet) from the bridge, Kennedy braked violently. This locked the front wheels. According to McHenry: "The car skidded 5 metres (17 feet) along the road, 8 metres (25 feet) up the humpback bridge, jumped a 14 centimetre barrier, somersaulted through the air for about 10 metres (35 feet) into the water and landed upside-down."
Investigators found it difficult to understand why he was crossing Dyke Bridge when he said he was attempting to reach Edgartown which was in the opposite direction. They also could not understand why he was driving so fast on this unlit, uneven, road. They also could not work out how Kennedy escaped from the car. When it was recovered from the water all the doors were locked. Three of the windows were either open or smashed in. If Kennedy, a large-framed 6 foot 2 inches tall man could manage to get out of the car, why was it impossible for Mary Jo Kopechne, a slender 5 foot 2 inches tall, not do the same?
Local experts could not understand why Kennedy (and later, Markham and Gargan) could not rescue Kopechne from the car. It also surprised investigators that Kennedy did not seek help from Pierre Malm, who only lived 135 metres from the bridge. At the inquest Kennedy was unable to answer this question.
There were also doubts about the way Kopechne died. Dr. Donald Mills of Edgartown, wrote on the death certificate: "death by drowning". However, Gene Frieh, the undertaker, told reporters that death "was due to suffocation rather than drowning". John Farrar, the diver who removed Kopechne from the car, claimed she was "too buoyant to be full of water". It is assumed that she died from drowning, although her parents filed a petition preventing an autopsy.
Other questions were asked about Kennedy's decision to swim back to Edgartown. The 150 metre channel had strong currents and only the strongest of swimmers would have been able to make the journey safely. Also no one saw Kennedy arrive back at the Shiretown Inn in wet clothes. Ross Richards, who had a conversation with Kennedy the following morning at the hotel described him as casual and at ease.
Kennedy did not inform the police of the accident while he was at the hotel. Instead at 9am he joined Gargan and Markham on the ferry back to Chappaquiddick Island. Steve Ewing, the ferry operator, reported Kennedy in a jovial mood. It was only when Kennedy reached the island that he phoned the authorities about the accident that had taken place the previous night.
Dr. Robert Watt, Kennedy's family doctor, explained his patient's strange behaviour by claiming he was in a state of shock and confusion and "possible concussion."
It was reported in The New Times magazine that Joseph Kopechne said that he and his wife rejected an autopsy because "we were led to believe that the autopsy was primarily to find out if my daughter was pregnant."