Every girl wants to be the popular one in school, the cheerleader, the one with the perfect life. Kristen Costas appeared to have it made to those at Miramonte High School. Kristen was aware of her status among her peers and wasn’t afraid to use it. However, the capitalization of that power proved to have fatal consequences.
Good-looking, awesome parents, and popular, Kristen Costas seemed to have a perfect life. Just about anyone was willing to do her bidding for the chance to earn favor in her eyes and be part of the ‘in’ crowd. From the outside, Kristen appeared poised to sail through school, garnering every experience a teenager could imagine. She didn’t bank on the dangerous results of jealousy being one of those experiences. In a flash, life for the idolized Kristen went from beauty and fun to a deadly nightmare.
Kristen Costas: When You Have It All
Beauty, talent, popularity, what more could a 15-year-old girl want? According to Simon Ayub of Tuko, Kristen Costas had these desirables in abundance. From the cheerleading squad to yearbook staff to a place within the Bobbies, a volunteer group that helped organize events, she gained acceptance into every realm. Traciy Reyes of Yahoo! News records that Kristen had a lovely home with a picture-perfect lawn, well-respected parents, and all the latest and greatest things a teen could want. She was a ‘cute, curly-haired cheerleader’ with the student body of Orinda California’s Miramonte High School wrapped around her finger. On the outside, it appeared that 1984 would be a stellar year for the lucky teen. According to Tuko, Kristen was not short on admirers or recognition.
Unfortunately, when a girl has it all, there’s a good chance it will go to her head. This was the case for Kristen. She was known to pull rank often and do her fair share of bullying due to her influence. Hurtful but not deadly. That was yet to be seen.
Popularity Gone Wrong
One day, Kristen’s parents received a phone call from an unverified fellow member of the Bobbies. The girl on the other end of the line explained that their daughter had been invited to a hush-hush dinner with the organization. Kristen’s parents passed on the message that a friend would be coming to pick her up to take her to this special event. As this was nothing unusual, Kristen was ready and willing to oblige. Unfortunately, she would never make it to the gathering. The event didn’t exist at all.
To the horror of Orinda, the envy-worthy cheerleader was found brutally murdered in a neighbor’s backyard the very night she was picked up for dinner with the Bobbies.
Her stab wounds–two to the stomach and two to the back–were severe, and she was rushed to the hospital. One of the wounds damaged her heart’s central artery, making the situation fatal. Nothing was to be done, and she died on June 23, 1984.
Also, the crime scene was secured immediately, and authorities began searching for the teen’s killer. They immediately zeroed in on Kristen’s peers, especially the ones who had reason to hate her.
All Fun and Games Until Someone Gets Jealous
Nancy Kane was a young woman who had a beef with Kristen due to bullying. The suspicion that Nancy might be the murderer led to questioning from the authorities. Her motives for hating Kristen appeared so strong that even Nancy’s mother feared that her daughter was the murderer. When the officers requested that Nancy be subjected to a lie detector test, she refused. She even went so far as to transfer her daughter to another school. It didn’t help that, according to Yahoo! News, the ‘chunky blonde girl’ was spotted in the crime scene’s vicinity on the day of the murder. However, when no solid evidence that Nancy was to blame for the brutal killing was discovered, investigators turned their attention to another of Kristen’s ‘fans’: Bernadette Protti.
Kristen Costas ‘fans’: Bernadette Protti.
Sixteen-year-old Bernadette’s life didn’t appear all that bad from the outside. She had hard-working parents who provided her with a decent home. However, according to Tuko, the teenager needed more satisfaction. She was at a rough age when she felt her parents didn’t care what she thought. The six Protti children, of whom Bernadette was the youngest, were raised within a strict Christian-Catholic framework. Her mother was a stay-at-home mom, and her dad was a retired public works officer. Bernadette believed her parents were too old and their chosen paths could not provide her with the luxuries her idol, Kristen, enjoyed. In addition, the teen was unhappy with her body and battled insecurities that she wasn’t attractive enough. These difficulties fueled her efforts to gain a good standing with Kristen.
Unlike Kristen, Bernadette wasn’t an automatic shoo-in for institutions like the cheerleading team or yearbook staff. However, she was hired for a student office job that allowed her to work side-by-side with Kristen. Serendipitous as this seemed, it didn’t instantly put her on the same playing field as her idol. It set the hopeful Bernadette in a precarious situation as Kristen took full advantage of her eagerness. The popular cheerleader talked the acceptance-starved young woman into doing things that, had she carried through with them herself, would jeopardize her position at the school.
According to Yahoo! News, Kristen appeared to ‘despise’ Bernadette and even threatened to tell the student body that she was ‘weird.’ In the world of immature teens vying for dominance, such a tragic threat prompted Bernadette to resort to drastic measures.
Obsession Gone Rogue
It was only after the police had been searching for Kristen’s killer for months that Bernadette Protti made a recorded confession. Though she’d laid low for a while, she eventually wrote a letter to her mother, confessing her guilt.
Desperate to earn a spot with the popular crowd, Bernadette had devised a last-ditch effort through a fake event invitation. According to Tuko, Bernadette issued the anonymous invite to Bobbie’s function. Having every reason to believe that one of her friends had called, Kristen arrived outside her house at the appointed time, ready to go. She was bemused to discover that Bernadette was her chauffeur. After telling them that she was headed to a babysitting job, the bullied girl had acquired permission to use her parent’s car.
Though Kristen hadn’t expected a ride from the unpopular girl, she got in the car.
During the drive, she noticed a knife and asked about it.
Bernadette explained that her sister had it on hand to cut produce. The eeriness only increased when Kristen realized that the supposed Bobbies event invite was essentially ‘second-hand’ and hadn’t been issued by one of her pals.
Anger Turned into Murder Kristen Costas
Deciding things had gotten too strange, Kristen got out of the car, stopping by the home of two other friends, Mary Jane, and Alexander, to call her parents. Her folks did not answer, so Alex gave her a lift. What she didn’t know was that they’d been followed.
As Kristen walked alone toward her home, Bernadette jumped out of her parent’s car, which she’d parked nearby. Crazed by the realization that she had made a fool of herself with this phony invitation, Bernadette became more desperate than ever to save her reputation. Her solution was to grab the knife from the car and stab Kristen, sealing the notorious fate she’d fought so hard to avoid.
Conviction of a Popularity-Thirsty Teen
On April 1, 1985, Bernadette was charged with second-degree murder, earning her a nine-year sentence.
She dodged first-degree charges because the authorities couldn’t prove that she’d planned Kristen’s death. She was transferred to the California Youth Authority in Ventura to receive her GED. After serving seven years of her sentence, she was placed on parole. She went on to marry and have a family of her own. There’s a possibility that she changed her name to Jannette Tomanka. According to Yahoo! News, Protti tried hard to maintain anonymity. Still, those fascinated by the case were relentless and eventually uncovered a picture of the now middle-aged teen killer. They published blogs about her though they were promptly removed from the public eye.
Many were disgruntled by the realization that the grown Bernadette Protti was living a whole life even after stealing the future of another. Some disapproved of her short-lived punishment, claiming she should have been behind bars longer. The unfair outcome prompted the launch of multiple movies and documentaries about the bizarre case. Among those who found the work unsatisfactory was Kristen’s father, Art Costas. Also, The Los Angeles Times records his disheartened statement on the matter: “My feeling is that the law has been served . . . . We’ve lost our daughter. I don’t believe the punishment will ever match the crime.”
If you enjoyed our feature on the death of Kristen Costas, read our articles on the Bucks County Murders and The Brutal ‘Scream Murder’.
