‘Bernadette Protti, Kirsten Costas: Cheerleader Murder On ID’s ‘1980s The Deadliest Decade,’ Plus The Obsession With Finding Bernadette Protti

The case of Bernadette Protti, the teen who murdered her classmate cheerleader Kirsten Costas in 1985, will be the next crime story to air on Investigation Discovery’s The 1980s: The Deadliest Decade. Authorities say after Kirsten Costas was stabbed multiple times and left for dead on a neighbor’s porch, they spent the next six months trying to find her killer. Eventually, they swooped in on Bernadette Protti, a jealous classmate who wanted to be friends with the popular cheerleader. On tonight’s show, you’ll hear from Nancy Kane, the former teen who was wrongly accused by residents of Orinda, California, of being the killer. Detectives who solved the case will also make an appearance on the show.


The 1980s: The Deadliest Decade: “The Cheerleader Murder” episode on ID

  • When a popular cheerleader is stabbed to death, local authorities begin the hunt for a chunky blonde-haired girl who was seen in the area. But as the real killer vanishes into the night, the town’s affluent residents have another suspect in mind.

Death of a Local Cheerleader

The murder of Kirsten Costas rocked Orinda, California, in 1984. Costas was a cute, curly-haired cheerleader who always moved through the in-crowds. Many of the girls wanted to be like Kirsten, including Bernadette Protti, a nice and seemingly mild-tempered teen who also attended the same local high school. What no one knew at the time was that Bernadette Protti had become obsessed with Kirsten Costas and desired to have her life. She wanted to come from a family whose parents had prestigious jobs. She wanted to live in a home with a manicured lawn, and she also wanted to have all of the latest expensive trinkets just like the Costases, according to People.

By all accounts, 16-year-old Bernadette Protti also lived in a nice home, and her parents, though older, were respectable hard workers. However, none of this was good enough for Bernadette.

A Planned Killing Or Did Something Go Horribly Wrong?

In her efforts to cozy up to Kirsten Costas, Bernadette Protti was often rejected and allegedly ridiculed by the cheerleader, who seemed to despise her very presence. To make friends with Kirsten once and for all, Bernadette decided to concoct a plan to lure Kirsten out of the home by calling her parents and inviting her to a sorority dinner with the Bob-o-Links. The caller never gave Kirsten Costas’ parents their name.

When Kirsten Costas’ ride came, she realized that it was Bernadette Protti. Even with this realization, Kirsten still got into the vehicle, where they talked for a bit before the situation took a twisted and tragic turn.

At some point, Kirsten Costas, who was already enraged, began calling Bernadette Protti “weird.” She also threatened to tell everyone at the school, which would have destroyed Bernadette’s reputation and made her the subject of intense ridicule in Orinda.

Bernadette had tried hard to fit into that society, and she was not about to live the horror of being run out of town, which is what happened to another classmate.

When police zeroed in on Bernadette Protti, she finally made a heartfelt confession to her mother and the police, according to the Los Angeles Times.

“I lost for cheerleader and I didn’t get the club I wanted and I didn’t get (on the) yearbook (staff). The things that got me mad was it hurt and I couldn’t change… like looks or money or popularity or things.”

In the end, Bernadette was arrested and convicted of the crime. Then, someone who knew about the case negotiated with television producers to make a movie based on it. In fact, in thinking back, the movie was based on an article by Randall Sullivan, who actually went to Orinda, California, to research the town and the murder. The name of the movie was Death Of A Cheerleader, also known as A Friend To Die For. It starred Tori Spelling.

The Movie and the Obsession With Bernadette Protti

In the 1990s, the blogThe Movies Based On True Stories Database linked fact and fiction it was the original Internet blog that matched the movie Death of a Cheerleader to the real people, Kirsten Costas and Bernadette Protti. The real names were changed in the movie, and back in the 1990s, old newspaper articles about these old cases were rarely available online. That kind of research, in those days, could only be found in public libraries.

Then in the late 2000s, the blogs Kirsten Costas Movie and Bernadette Protti Found revealed that Bernadette Protti was released from prison after a few short years, and from there, she moved to another state and changed her name before she married.


The Bernadette Protti Found blog also revealed that with her secret identity, Bernadette Protti managed to carve out a good life for herself by attending college and studying medicine and science, allowing her to land high-paying jobs.

However, Bernadette Protti’s new name was never released to the blog readers, and the blog merely told readers about a picture that it had found of an adult Bernadette Protti, a picture that was soon deleted after the blogs appeared. Before this information was shared, the general Internet community had no idea what happened to Bernadette Protti after she was convicted. This revelation shocked and horrified readers, who believed that Bernadette had no right to live in anonymity while Kirsten Costas was dead and her family was left devastated. They also believed that seven years was not enough time in prison. However, some readers believed that it was best not to reveal her true name.

For years, blog readers relentlessly tried to uncover Bernadette Protti’s new name. Eventually, her new identity was revealed, along with a photo of the real Bernadette, which had originally vanished from the internet years earlier. Today, you’ll find a slew of blogs dedicated to the case based on the information found in news articles that are now available online and the original blogs that exposed what happened to Bernadette Protti after her release.

In addition to the movies, Death of a Cheerleader, aka A Friend to Die For, the Kirsten Costas case was also profiled on the Lifetime Television documentary Killer Kids and Deadly Women.

It’s a fascinating but sad case that is embedded into American culture and sure to be talked about for decades to come. To find out more about the cheerleader murder case, tune into The 1980s: The Deadliest Decade tonight at 9/8 p.m. Central on Investigation Discovery.

What’s Your Opinion?

  • Do you think Bernadette Protti’s identity should have been revealed or kept secret since she served her time in prison?

[Featured Image by Investigation Discovery]

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