A young actress, an obsessed stalker and a Hollywood murder that changed America

The prosecutor was studying the killer's confession, trying to understand what was wrong with it. In her first few viewings of the videotape, Marcia Clark had the gnawing sense that he was lying. She took careful notes. She watched to the end, rewound and watched again.

On the tape, Robert Bardo was in a room at Men's Central Jail in downtown Los Angeles, telling his defense-appointed psychiatrist how he had stalked and killed 21-year-old actress Rebecca Schaeffer. He was a misfit from Tucson, a high school dropout who had once worked the grill at Jack in the Box but couldn't hold a job.

He had been fixated on the actress for four years. He taped every episode of "My Sister Sam," the sitcom in which she played a bubbly, innocent teenager from 1986 to 1988. He wrote her endless letters. He quoted John Lennon lyrics. Once, she sent him a personalized response telling him that his letter was one of the nicest she'd received. Friends had warned her that even the most innocuous personal note could be misinterpreted. It seemed to inflame