31 years ago, four teen girls were murdered in a yoghurt shop. DNA evidence could solve the case.

Content warning: This story includes mentions of sexual assault that may be distressing to some readers.

In Austin, Texas, there once was a frozen yoghurt chain store called 'I Can't Believe it's Yogurt'.

It was popular with families and young people throughout the '80s and '90s. In 1991, there were two 17-year-old girls who worked at the Austin store - Eliza Thomas and Jennifer Harbison.

Today, that yoghurt shop is no more. Over the years it has been replaced with a payday loan store, the only noticeable remnant of its origins being a nearby plaque that commemorates four young lives lost on December 6, 1991.

Their names were Eliza Thomas, Jennifer Harbison, Sarah Harbison and Amy Ayers.

The quadruple murders at the yoghurt shop have long haunted the city of Austin, with legal justice yet to be served. 31 years later, police still hope DNA evidence will solve the case. 

Watch: the case unpacked 31 years later. Post continues below.

The victims. 

Jennifer and Eliza were working in the yoghurt shop on that Friday night in December 1991. Nearing the end of their shift, Jennifer's younger sister Sarah Harbison and Sarah's friend Amy Ayers visited the shop.

Sarah was 15, Amy was just 13. The younger pair planned to get a lift home with Sarah's older sister after the yoghurt shop closed at 11pm. None of the girls made it home that night.

Just before midnight, a police patrolman reported a fire in the shop, and first responders discovered the bodies of the girls inside. The girls had been bound, gagged, and died of bullet wounds to the head. Some of them had been sexually assaulted.

More than 1,000 people attended a church service for the girls, and a candlelight vigil drew even more mourners six months later. 

Eliza's sister said to the TV program 48 Hours that it took her a long time to grapple with the fact her sister wouldn't be coming home again. 

"I remember fantasising for days that my sister had somehow escaped and ran away and was hiding ... I was constantly fantasising that she was going to come back. I fell apart under that pressure."

Amy Ayers, Eliza Thomas, Jennifer Harbison and Sarah Harbison. Image: Police. 

The investigation.

Investigators suspect multiple people took part in robbing the shop and killing the girls.

It proved difficult for authorities, however, considering the fire had destroyed much of the evidence.

In 1999, Austin police announced that four men had been charged with capital murder in the case. A sense of relief swept Austin. These men, who at the time of the murders were teenagers, were now in their 20s. 

They had been interrogated by various detectives and confessions were subsequently obtained by some of them. The four men were Robert Springsteen, Michael Scott, Maurice Pierce, and Forrest Welborn. Two of the four were sent to trial, entirely due to self-incriminating statements. But both retracted their confessions before trial.

Scott was placed on death row in 2001 and Springsteen was sentenced to life behind bars in 2002. But the convictions didn't hold. A detective had held a gun to Scott's head during a multi-day interrogation. 

New and improved DNA tests also came back without any matches. Scott and Springsteen were released on bond in June 2009 and their charges were dismissed. It's now assumed the confessions of these men were coerced.

Investigators were back to the drawing board, trying to find the killers.

In recent years, new teams of investigators and prosecutors have worked on the case. There have been updated efforts to get new leads via DNA advances.

Authorities began searching through a public online DNA database used for population studies to see if there was a match to the DNA evidence found on the four girls. And there was an initial match. 

The doorway of the 'I Can't Believe It's Yogurt' shop following the murders of the four girls. Image: Getty.

The downside however is that this new lead's DNA was submitted anonymously by the FBI into this database, and the FBI wouldn't budge on unearthing who this DNA belonged to due to privacy restrictions.

After pressure from the public, media and politicians, the FBI agreed to work with the Austin Police Department to see if further testing could be done. However in 2020, more advanced testing revealed that the sample from the crime scene no longer proved to be a match to the sample in the public DNA database.

But with DNA research advancing quickly, investigators hope new advances will lead in science to a match.

Then in 2022, lawmakers passed a bill with this case directly in mind.

The 'Homicide Victims' Families Rights Act' bill aims to help make cold cases easier to solve by putting pressure on the system to keep giving the cases the attention they deserve.

The legislation makes it compulsory for federal law enforcement to review case files and apply the latest technologies and investigative standards.

The impact of their deaths.

Eliza's mother said to one news outlet she decided to move away from Austin because being there hurt too much.

"Running into people who were constantly asking how the case was going was very hard on me and especially my daughter," she said. 

Eliza's mother died in 2015, never knowing who was responsible for Eliza's murder.

The Harbison family lost their only children: daughters Jennifer and Sarah. As their mother Barbara said: "My life was focused around them from here to eternity. Someone took eternity away from me."

Bob Ayers is the father of the youngest victim, Amy. 

"I lost my daughter. I lost my first dance. I won't see her graduate. I won't see her become a veterinarian… She was a Daddy's girl," he said.

31 years later, Amy's brother and sister-in-law still celebrate her birthday, often making a cake at home or sharing a restaurant dessert in her honour. 

"We remember her every day. It's 31 years of trying and not giving up," Amy's brother said. "If it takes 31 more years than so be it. There will be a resolution to this - we won't give up."

If this has raised any issues for you, or if you just feel like you need to speak to someone, please call 1800 RESPECT (1800 737 732) – the national sexual assault, domestic and family violence counselling service.

Feature Image: Police/Getty/Mamamia.

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