The night of Friday, Dec. 6, 1991, was supposed to be a happy, fun one for four young Texas teenage girls.

Sarah Harbison, 15, and her friend Amy Ayers, 13, were waiting for Sarah’s older sister, Jennifer Harbison, and their friend Eliza Thomas, both 17, to finish their shift at an I Can’t Believe It’s Yogurt! shop so they could head to a sleepover.

As Thomas and Harbison cleaned up — putting away toppings, washing dishes and taking out the trash — a man entered the store.

After forcing the terrified girls to strip naked, he sexually assaulted three of them before binding and gagging them with their own underwear. Next, he shot them each in the head at close range. Then, in one final act of vitriol, he set the store ablaze, burning the girls’ bodies beyond recognition and destroying almost all traces of evidence.

Scene of the crime on Dec. 6, 1991.

Courtesy Tony Garcia

The victims’ families grieved, and the case went cold for 34 years — until Sept. 29, 2025, when authorities announced at a news conference that they had identified known serial killer and rapist Robert Brashers, who was 33 when he committed the crime and is now deceased, as the monster responsible for the quadruple homicide that became known as the Yogurt Shop Murders.

Victims of the 1991 Yogurt Shop Murders, clockwise from top left: Eliza Thomas; Sarah Harbison; Jennifer Harbison; Amy Ayers.

Austin Police Department

Among those at the press conference was Sonora Thomas, 47, who was 13 when her older sister, Eliza, was killed. In an exclusive interview with PEOPLE, she revealed that after years of wondering, she was “in shock” at learning that a serial killer took the lives of her sister and the other girls. “In some ways, there’s a strange relief, because the act was so evil,” she says. “This is an evil person who did this.”

Presumed serial killer Robert Brashers.

Missouri State Highway Patrol

Also impacted by the revelation were the crime’s three original suspects, Michael Scott, Robert Springsteen, Forrest Welborn, and the widow and daughter of the fourth suspect, Maurice Pierce, who for years had been publicly condemned as killers when they were innocent.

The final chapter of the tragic saga is the focus of the fifth episode of HBO’s acclaimed docuseries, The Yogurt Shop Murders, which is currently streaming. (An exclusive clip is shown below.)

The latest documentary by Emmy-nominated director Margaret Brown, the four-part series debuted in August 2025, just one month before the pivotal moment when DNA from under Ayers’ nails definitively linked Brashers to the murders.

“It’s the worst thing that can happen to you,” Brown tells PEOPLE. “For your daughter to be sexually assaulted and murdered, and then to not know who did it for 34 years.”

Titled “The End of Wondering,” the final episode follows how Austin Detective Dan Jackson solved the case, the families’ long-awaited answers, and the lasting toll on those once suspected.

Marisa Pierce, whose father Maurice Pierce was killed at 35 in a 2010 police confrontation, says in the episode that “it just doesn’t feel like it’s real justice.” She adds, “I want to be respectful to everybody, but my dad will never come back. It’s a little too late for him.”

Reputations Destroyed

Back in 1991, the I Can’t Believe It’s Yogurt! store in a cookie-cutter strip mall on West Anderson Lane was where local kids hung out after school. “That was our second home,” says Thomas, who would ride her bike to the store to get free samples from Eliza.

The horror of Dec. 6, 1991, shattered any sense of normalcy for Thomas’s family, the other victims’ families and the city of Austin — and cast a lasting shadow of suspicion over the original suspects.

Questioned and released by police in 1991 when they were high school students, the four original suspects’ lives changed forever in 1999 when a police task force revisited the case.

During marathon re-interrogations, Springsteen and Scott implicated each other and confessed to the crime under police coercion, they said.

That same year, all four were arrested and charged with capital murder. Tried and convicted in 2001, Springsteen was sentenced to death. Convicted in 2002, Scott was sentenced to life in prison without parole. Welborn’s charges were dropped in 2000 when a grand jury failed to indict him. Jailed for three years, Pierce was released in 2003 when his charges were dismissed.

Finally, in Feb. 2026, a district judge formally declared all four innocent. Though they were officially cleared, they remained haunted by the ugly stigma of the 𝒶𝓁𝓁𝑒𝑔𝒶𝓉𝒾𝓸𝓃𝓈. “A lot of people think of me as a murderer,” Welborn says in the episode. “It’s been really difficult.”

Unraveling a Decades-Old Mystery

The long road to solving the crime was marked by dead ends, cold leads and frustration, Jackson tells PEOPLE.

Asked to take a fresh look at the murders in 2022, Jackson reviewed the case and began retesting items found at the scene, especially since imaging technology had greatly improved over the years.

Detective Dan Jackson.

Courtesy of HBO

In June 2025, he sent in a spent .380 shell casing found in a drain for retesting. On July 2, 2025, he got a call that the shell casing matched a bullet used in an unsolved 1998 murder in Lexington, Ky.

That’s when he asked investigators in Lexington to perform a Y-STR profile on DNA left behind at that crime scene, which looks for DNA sequences found on the male Y-chromosome, he says. He and his team reached out to all the public labs in the country and asked them to search their databases for a Y-STR profile that matched the unknown profile from the yogurt shop.

A few weeks later, officials in Greenville, S.C., called with astonishing news: that they had the same profile in their database, which belonged to a criminal named Robert Brashers. Jackson learned that in 2018, genetic genealogist CeCe Moore had used DNA to solve the 1990 cold case murder of Jenny Zitricki, who was killed by Brashers. “We just took off from there,” says Jackson.

Trying to confirm that Brashers was in or near Austin at the time of the murders, Jackson reached out to the FBI, which gave him a long list of the dates when Brashers had been stopped or arrested under his name or aliases. “I sorted it chronologically and there it was,” he says.

“On December 8th, 1991, less than 48 hours later, he was stopped leaving Texas near Las Cruces in a stolen truck,” he says. He was arrested but fled to Georgia, he says. After learning more about Brashers, in Sept. 2025, he became cautiously optimistic that “this is probably our guy,” Jackson says. “But I’m not 100 percent.”

Knowing that Amy fought the killer in her last precious moments alive, Jackson sent her fingernails to be tested to see if Brashers’ DNA was left behind. “Amy’s final moments on this Earth were to solve this case for us,” Jackson said at the press conference. “It’s because of her fighting back.”

Brashers died by suicide in 1999 after a standoff with police, when authorities came to arrest him.

Still Investigating

Even though the Yogurt Shop case has been solved, Jackson is still investigating other crimes Brashers may have committed before his death. “I’m sure he’s good for more murders,” Jackson says.

Brown is hoping the final episode will help lead authorities to more of Brashers’ potential victims. “Hopefully people will watch it and make some connections,” she tells PEOPLE. “That’s the hope.

As for the initial suspects, on May 13, the city of Austin announced that it had agreed to a settlement with the three surviving suspects and Pierce’s family for $35 million in restitution for being wrongly accused of the murders. As part of the settlement, the city agreed to ban unsupervised interrogations of underage suspects.

As the final chapter of this devastating part of Thomas’s life winds to an end, she says she still thinks about her sister every day.

She also thinks of her mother, Maria Thomas, who “was so tortured by the unanswered question,” she says, “she died by suicide 10 years ago,” at age 60.

She is still plagued by the fact that the murders were so random, she says. “It’s painful to think how easily this could not have happened,” she says. “Our lives would’ve all been different.”

If you or someone you know has been sexually assaulted, please contact the National 𝒔𝒆𝒙𝒖𝒂𝒍 𝒶𝓈𝓈𝒶𝓊𝓁𝓉 Hotline at 1-800-656-HOPE (4673) or go to rainn.org.