Mary Richardson Kennedy, 52, an architect who struggled with drug and alcohol charges in recent years, hanged herself.
The Westchester County Medical Examiner's office said Thursday that she died of asphyxiation due to hanging. A person familiar with the investigation into her death says that authorities have concluded that she hung herself. The person was not authorized to release the information, and spoke on condition of anonymity.
Kennedy's body was discovered Wednesday afternoon at the family's property in Bedford.
Her death came after several hard years for the family. Her husband, Robert Kennedy Jr., a prominent environmental lawyer and the son of Sen. Robert F. Kennedy, had filed for a divorce in 2010. The two had married in 1994 and had four children together.
On Thursday morning, people who knew the family, and some strangers, as well, dropped by home to leave flowers at the front door.
"I think every family has its tragedies. But this is too much. You have to feel for them," said Kim O'Connell, 59, of Bedford Hills, as she dropped off a bouquet of Calla lilies. She said she had met Mary and Robert while working at their health club.
"I just thought she was just a lady. I woke up this morning, and I wanted to do something," she said.
Associated Press writer David B. Caruso contributed to this report.