Story highlights Jean S. Harris was convicted in 1981 of killing her longtime lover, Dr. Herman Tarnower

Tarnower wrote a best-selling book touting the benefits of a high-protein, low-fat diet

The case ignited a national debate about Harris and the shooting

She claimed she accidentally killed Tarnower in a struggle for a gun

Jean S. Harris, the headmistress whose trial for the murder of the "Scarsdale Diet" doctor captured the attention of a nation with its details of sex and infidelity, has died, her son said Friday. She was 89.

Harris died in her sleep Sunday at a retirement community in New Haven, Connecticut, her son James said.

When she was arrested for the March 10, 1980, shooting death of longtime lover Herman Tarnower, the celebrity doctor behind the best-selling book "The Complete Scarsdale Medical Diet," the case ignited a national debate about whether she was a woman scorned or a victim of abuse.

Harris claimed she had driven to Tarnower's house to see him one last time and then kill herself, but accidentally shot him four times during a struggle for the gun.

Feminists rallied to her defense, painting the case as that of an aging woman being pushed aside by her lover in favor of a younger woman. The prosecution and her critics said it was a case of jealousy.

More than a hundred journalists reportedly turned out to cover the trial, which lasted 14 weeks.

Harris met Tarnower in 1966, shortly after she divorced her husband. She was 43. Tarnower was 55.

At the time of the killing, she was the headmistress of Madeira School, a private, exclusive all-girls school.

During the trial, it was revealed that Tarnower once asked Harris to marry him and then changed his mind because he could not stop seeing other women. Harris accepted Tarnower's position and stayed with him for nearly 14 years.

It was during their time together that Tarnower, a cardiologist with a practice in the New York City suburb of Scarsdale, wrote a book touting the benefits of a high-protein, low-fat diet. The book became a bestseller and earned Tarnower millions.

During the trial, Harris testified for more than a week about her relationship with Tarnower and the events that led up to the shooting.

On the night of the shooting, she said she drove to his house and found him asleep. Then she saw a woman's nightgown and hair curlers and grew enraged after realizing they belonged to Tarnower's 37-year-old nurse, who he had begun taking to parties and other events in Harris' place.

According to transcripts, Harris said she pulled her gun out to shoot herself in front on him. When he tried to stop her, she testified, the gun went off. Tarnower was shot four times.

The case generated a number of books and two television movies: "The People Vs. Jean Harris" in 1981 and "Mrs. Harris" in 2006.

Harris was convicted by a jury in 1981 of second-degree murder and was sentenced to 15 years to life. She served nearly 12 years before being granted clemency in 1992 by then-New York Gov. Mario Cuomo because of health problems.

At her sentencing, she denied murdering Tarnower, saying she loved him.

After her release, she established a foundation that raised money for the children of women in prison in New York.

In addition to James, she is survived by another son, David.