Credit: Seattle Times, Betty Udeson/AP

Ann Rule, a famed true-crime author most widely known for her profile of serial killer Ted Bundy, has died.

Rule died Sunday night at Highline Medical Center in Durien, Washington, said Scott Thompson, a spokesman for CHI Fransiscan Health. The cause of death is not yet known, according to Thompson. Rule was 83.

Born in Lowell, Michigan, Rule was introduced to the world of crime at a young age. While neither of her parents worked in law enforcement, many members of her direct family did, which feuled her desire to pursue a career in the field, according to her website. She was also a dedicated advocate for victims of violent crimes.

Rule wrote 30 New York Times bestsellers, in addition to more than 1,400 articles. Her first bestseller, The Stranger Beside Me, followed her relationship with Bundy, with whom she worked at Seattle’s Crisis Hotline. She was fascinated to find out what exactly made people become criminals, and focused much of her research on delving into their upbringings and backstories.

“Sometimes people turn their noses up at true crime writing and readers wonder if there’s something wrong with them for finding this subject so interesting,” Rule said in an interview posted on her website. “My readers tend to be very gentle people; it’s just that we are all tremendously curious about what makes some babies grow up to be savage criminals and others law-abiding citizens. If we don’t know what causes aberrant behavior, we will never be able to prevent it. I write about it because I love to, because it’s my job, and because I’m curious about psychopathology, too. But I also want to help victims, their families, and to save potential victims.”

Several of her books have been adapted into films, including The Hunt for the I-5 Killer (2011), Too Late to Say Goodbye (2009), and And Never Let Her Go (2001). Small Sacrifices, a television adaptation of her novel starring Farrah Fawcett, won the Peabody Award in 1989.