Are two never-identified customers key to solving Austin's yogurt shop murders?

[This story was originally posted on February 5, 2022. It was updated on August 27.]

It has been more than 30 years since four teenage girls were murdered in an Austin, Texas, yogurt shop and the case remains unsolved. At one point, there were arrests and then convictions, but those convictions were later overturned on appeal, and ultimately, new DNA technology raised doubts about the involvement of those initial arrestees. 

The case has left investigators at what appears to be a standstill, but as correspondent Erin Moriarty reported in this week's "48 Hours," there is a theory that two never-identified men seen in the yogurt shop on the night of the murders may have been involved in the unsolved killings that have haunted Austin for decades. 

On December 6, 1991, 17-year-old Eliza Thomas, 13-year-old Amy Ayers, and two sisters, 17-year-old Jennifer Harbison and 15-year-old Sarah Harbison, were tied up and shot in the head in an "I Can't Believe It's Yogurt!" shop in Austin. 

The city had never seen a crime quite like it. Eliza and Jennifer had been working in the yogurt shop that night. They were getting ready to close when Jennifer's sister, Sarah, and their friend, Amy, met them there to head home. Investigators believe at least two men entered the shop and committed the brutal crime before setting the place on fire, destroying much of the evidence.

John Jones worked for the Austin Police Department at the time of the crime and was the lead investigator on the case. He has since retired. Jones told Moriarty that as part of the early investigation, he and his team tracked down customers who were in the yogurt shop on the day of the crime to see if they noticed anything suspicious. According to Jones, multiple customers described two men who "looked out of place" sitting in the shop just before it was due to close. Neither man was reported to have purchased frozen yogurt — instead, only a drink.

"They never have been identified. And we did everything. … We even hypnotized some folks," Jones told Moriarty.

Despite investigators' efforts, that lead went nowhere and eventually the case went cold. Then, in 1999, nearly eight years after the murders, there was a break in the case when new investigators decided to re-examine a different old lead.

Robert Springsteen, Michael Scott, Maurice Pierce and Forrest Welborn were only teenagers at the time of the crime. They, too, had landed on Jones' radar early on after one of them, Maurice Pierce, was arrested with a gun at a mall near the yogurt shop in the days after the crime. Back then, the men were questioned by Jones and his team but were subsequently released for lack of evidence. 

In 1999, the new investigators decided to re-question the men. Two of them, Robert Springsteen and Michael Scott, confessed to the yogurt shop murders and implicated Pierce and Welborn in the process. All four men were subsequently arrested.

But it wasn't long before Springsteen and Scott recanted their confessions, saying they were coerced. Charges were ultimately dropped against Pierce and Welborn due to lack of evidence. 

Springsteen and Scott were the only two to go on trial. They were both convicted, but years later, their convictions were overturned on constitutional grounds. The Sixth Amendment gives defendants the right to confront accusers and in Scott and Springsteen's trials, their confessions were used against one another, but they weren't allowed to question each other in court.

Prosecutors intended to retry Springsteen and Scott, but before doing so, they ordered DNA tests on vaginal swabs taken from the victims at the time of the murders. By this point, investigators had come to believe at least one of the victims had been sexually assaulted, and prosecutors wanted to take advantage of a fairly new type of DNA testing called Y-STR testing. It searches for male DNA only. 

No one expected what it would reveal. As a result of the testing, a partial male DNA profile was obtained from one of the victims, but to the surprise of the prosecutor's office, the DNA sample did not match any of the four men who had been arrested. Charges were dropped against Springsteen and Scott, and they were released from prison after spending 10 years behind bars.

Attorney Amber Farrelly worked on both Scott and Springsteen's defense teams. She is adamant that police had it all wrong when they arrested Scott, Springsteen, Welborn and Pierce. She told "48 Hours" she believes those two unidentified customers from the yogurt shop are who police should really be fixated on.

While working on Scott and Springsteen's defense teams, Farrelly was tasked with sifting through old police records, including those interviews Jones and his colleagues had conducted with customers who visited the yogurt shop on the day of the murders.

"They (police) have accounted for and interviewed 52 people that were in the yogurt shop that day," Farrelly told "48 Hours'" Erin Moriarty.

Farrelly says several of those customers mentioned the two men who were seen sitting in the yogurt shop just before it was due to close that night.

"We have no names to them. And when you look at — when you step back and you look and you think, 'They've talked to 52 people and didn't miss one person from 4:30 until 11:00 at night. And several people talk about a guy or two guys, and they describe them in the same manner? And we don't know who those two guys are? And they've never called in? … That raises, in my opinion, the suspicion… that these are the gentlemen who did it," Farrelly said.

"Were those two men who've never been identified the last people in the yogurt shop, as far as you know?" Moriarty asked Farrelly.

"Absolutely," Farrelly responded.

Farrelly says the men were described as "kind of leaned over the table, talking to each other and kind of whispering, like they didn't want anybody to hear what they were saying."

She says that one of the men was described as having light, short hair, "like a dirty blonde," and was said to have been about 5'6" tall and in his late 20s or early 30s. She says the other man was described as being "bigger," and both were observed wearing big coats. One, she says, is thought to have had a green "Army fatigue kind of looking jacket" and the other is thought to have had a black jacket. According to Farrelly, the men are believed to have been driving a green car that evening.

John Jones, the former lead investigator on the case, is still haunted by the unsolved yogurt shop murders even though he has long retired. He told "48 Hours" he still wonders about those unidentified customers.

"Yeah, it's kind of a question to me that to this day, they haven't been identified," he said. "Is that evidence that they did it? No, but that's evidence that we really need to talk to them."

If you have information about the yogurt shop murders, call 512-472-TIPS.