It has been 30 years since firefighters doused the flames tearing through a North Austin yogurt shop and discovered the bodies of four teenage girls who had been bound, gagged and shot in the head.
The horrific crime shocked the city, unsettled investigators and devastated the teens' families.
More than 1,000 people attended a church service for the girls, and a candlelight vigil drew even more mourners six months later as days turned into weeks, then months without an arrest.
Evidence, destroyed by fire and washed away by firehoses, was hard to come by, and rewards for information grew from $25,000 to $125,000 as months turned into years with still no arrests. A task force of federal, state and local investigators formed in 1997 but disbanded less than a year later.
Two months shy of the eighth anniversary of the Dec. 6, 1991, slayings, Austin police in 1999 announced that four men had been charged with capital murder in the case. A sense of relief swept Austin.
Two of the men confessed to the late-night murders and were convicted, and one was sentenced to death, before their convictions were overturned on appeal and prosecutors declined to return to court. The two other suspects were never tried. All four insisted they were innocent, including the two who recanted their earlier confessions, saying they had crumbled under the pressure of police interrogators.
Thirty years later, the full picture of what happened that night is still unclear and justice remains elusive.
At the site today, a ground-level plaque dedicated to the girls stands in the parking lot of the strip center where the I Can't Believe It's Yogurt store stood, its space occupied by different businesses.
"Forever in our hearts," the metal plaque on a granite base says below the four names: Amy Ayers, Sarah Harbison, Jennifer Harbison and Eliza Thomas. Recently, a bouquet of dried flowers lay alongside.
The evidence: Before the yogurt shop case went cold, leads and clues hard to come by
A couple who bought frozen yogurt told police that one of the victims locked the door behind them as they left that Friday night near closing time.
At 11:47 p.m., a police officer on patrol reported a fire at the shop. The front door was still locked. The back door was not. Investigators, who found no sign of forced entry, suspect multiple people took part in robbing the shop and killing the girls.
While the families mourned and the city struggled with the enormity of the crime, police received their first confession that same month: A teenage girl said she and her boyfriend committed the crime. The confession proved false.
In August 1992, Austin police begin searching for three men who had been indicted in an unrelated abduction and sexual assault, saying they also wanted to question them in the yogurt shop murders. With much fanfare, Mexican authorities announced two months later that they had arrested two of the men, saying both would be charged with the Austin murders after one had confessed.
The confession, however, was later recanted as the suspect accused Mexican authorities of torture. That lead dried up, as well.
By the two-year anniversary of the murders, police had investigated more than 5,000 leads. They still had made no arrests in the case.
More: 30 years later, Austin reporter recounts covering horrific yogurt shop murders
The victims: 'Gone for so long,' girls' families continue to mourn
Barbara Ayres-Wilson lost two daughters that night.
"My children have been gone for so long," she said in a recent interview with the American-Statesman. "I have memories of them, but they are fleeting as I get older. I think more now about when I will join them."
Each of the girls shared a love of animals, particularly of horses and lambs. They gravitated to the same Future Farmers of America chapter, where friendships quickly bloomed.
Jennifer Harbison, 17, was a senior at Lanier High School, while her 15-year-old sister, Sarah, was a freshman on the same campus on Payton Gin Road in North Austin.
The Harbisons spent their early childhoods in Texarkana, but moved to Austin with their mother after their parents divorced. They had attended private Catholic school but transferred to Lanier High.
Along with being active in the school's FFA chapter, both were athletes. Jennifer ran track, while Sarah competed on the school's volleyball and basketball teams.
Jennifer's parents had recently purchased a car for her, but with the condition that she get a job to help make payments. That's why she worked at the yogurt shop.
Eliza Thomas, also a 17-year-old Lanier senior, had similarly begun working at the store to make extra money. She had joined Lanier's FFA chapter and participated in the school's welding and agriculture program.
Amy Ayers, the youngest victim, was a Burnet Middle School student but also participated in Lanier's FFA program. That's how she became friends with Sarah. On the night of the murder, Amy was going to spend the night at the Harbison home. She and Sarah had been together at Northcross Mall and walked about 10 minutes to the yogurt shop to ride home with Jennifer.
Thirty years later, Amy's brother and sister-in-law, Shawn and Angie Ayers, still celebrate her birthday, often making a cake at home or sharing a restaurant dessert in her honor.
"Everybody got cheated," Angie Ayers told the Statesman recently. "I think, would we all be riding horses together? Would your kids be friends? Think of everything we missed. If she had gone to college. Marriage. You can't get any of that back."
The case: Charges, trials, convictions - but justice?
Eight days after the murders, Austin police arrested 16-year-old Maurice Pierce with a .22-caliber revolver at Northcross Mall, a few blocks east of the yogurt shop. Pierce said he had loaned the gun to a friend, Forrest Welborn, 15, who had used it in the yogurt shop murders and told him about it later.
Police investigated but rejected the claim, assuming it was an attempt to deflect attention from a charge of unlawfully carrying a weapon.
But in 1999, when the department's cold case unit took another look through the evidence, officers decided to take a closer look at Pierce's claim.
That October, Austin police made their first, and only, arrests in the case - Pierce, Welborn and two of their friends, Robert Springsteen IV and Michael Scott. Springsteen and Scott, police announced, confessed to the crime to police interrogators.
"On Dec. 6, 1991, we - as a city - lost our innocence,'' then-Mayor Kirk Watson said. "Today, we regain our confidence."
Springsteen and Scott later recanted their confessions, saying they were coerced during lengthy interrogations, but both were found guilty. Springsteen was sent to death row in 2001; Scott got a life term a year later.
With no physical evidence tying them to the crime - ballistics tests in 2000 had shown that the gun Pierce was caught with probably was not used in the crime - Springsteen's and Scott's confessions were the centerpiece of the case against them.
Their confessions also became the center of appeals that would overturn their convictions.
The appeals: Court steps in to reverse yogurt shop convictions; DNA not a match
Pierce and Welborn never went to trial in the case.
Charges were dropped against Welborn in 2000 after two grand juries declined to indict him. Pierce spent three years in jail before he was freed in 2003 when prosecutors reluctantly admitted that they didn't have enough evidence to convict him.
News for prosecutors would only get worse.
Scott, who had been interviewed for 20 hours over five days at Austin police headquarters, initially said he knew nothing of the crime before saying he tried to rape one girl and shot two others. He also implicated Welborn, Springsteen and Pierce in the crime, which he said started as a robbery because Pierce needed money.
After Scott signed a confession, police went to West Virginia, where Springsteen had moved in 1992.
Springsteen first told detectives during his five-hour videotaped interview that he was never within 100 yards of the shop. But as the questioning wore on, he eventually admitted to shooting and raping one of the girls and said that Welborn, Pierce and Scott also were involved.
Springsteen's conviction, however, was overturned in 2006 when the Texas Court of Criminal Appeals ruled that Scott's confession - read to jurors at Springsteen's trial to corroborate his confession - had been improperly used against him in violation of his Sixth Amendment right to cross-examine witnesses.
A year later, the court came to the same conclusion about Scott, tossing out his conviction as well.
Prosecutors insisted that they believed the men were guilty and prepared for a new trial.
Big case turns into big fight: DNA discovery in yogurt shop murders sparks FBI standoff
In June 2009, when prosecutors moved for another trial delay, the judge ordered Springsteen and Scott released from jail on bond.
Four months later, prosecutors were back in court, this time to formally drop the charges against the two men for lack of evidence. Using advances in technology, tests found DNA on several crime-scene samples, but none were linked to Springsteen, Scott or the other two suspects.
Afterward, Springsteen lawyer Joe James Sawyer said his client believed that it was the families of the slain girls, not the suspects, who had suffered the most.
"We should reserve our sympathy for the families," Sawyer said.
In 2010, Pierce died after an Austin police officer shot him in a confrontation in North Austin after stopping him for a traffic violation. Pierce stabbed the officer, who survived his injuries, after years of what his family said was police harassment.
What's next: Can there be resolution in the yogurt shop murders?
Retired Austin police Detective John Jones was the first lead investigator on the case and spent about three years working to learn who killed the girls.
"I had hoped it would be solved by now, but there is no statute of limitations on murder," Jones told the Statesman recently. "People say, 'Well, what if it is something you overlooked?' Fine. OK. I'm good with that. Just so it can be proven that they did it."
In recent years, new teams of investigators and prosecutors have worked on the case, trying to identify any new or overlooked information that might lead to the killers. Detectives thought they had received a significant lead in 2017 through DNA advances.
More: 'Justice is far gone': Can the Austin yogurt shop murders ever be solved?
They fought to obtain information from the FBI, but the agency stood by its position that the information was protected by federal law. Scientists also have cast doubt on whether it could help lead to a suspect.
Investigators were able to extract male-only DNA called Y-STR from a forensic sample.
However, "Y-STR DNA testing, or genetic genealogy, is much less informative," said CeCe Moore, a genetic genealogist who has assisted criminal investigators. "It's not meaningless, but there's a much lower chance that it's going to help lead to an identification" than a more typical forensic DNA sample.
A break in the case more likely will come from a confession by the killer or someone who knew the killer, Moore said.
However, the case is so well known that such confessions might not be credible, and so much time has passed that it would be difficult for prosecutors to corroborate any admission to the crime.
"Cases of this type often will generate hundreds, thousands, even tens of thousands of suspects," said Kim Rossmo, a Texas State University criminal justice professor. "So they're going to need strong evidence."
Previous coverage of the Austin yogurt shop murders from the Statesman's archive
Dec. 9, 1991: Teens' violent deaths mourned.
Oct. 23, 1992 : Arrests made in yogurt shop case, leaving victims' families shaken.
April 16, 2001: First trial in 1991 yogurt shop killings starts today.
June 2, 2001: Convicted killer in yogurt shop slayings condemned.
May 25, 2009: Robert Burns Springsteen IV's rights were denied, Texas appellate court says.
Oct. 29, 2009: Yogurt shop case charges dropped
Dec. 25, 2010: Yogurt shop suspect dies in shooting.
April 24, 2016: Suspect in yogurt shop killings: Clear my name.
Austin Police Department homicide tipline
Austin police say they are still actively investigating the murders of four teenaged girls at an I Can't Believe It's Yogurt shop 30 years ago. Anyone with information is asked to call the Austin police homicide tip line at 512-477-3588 or Crime Stoppers at 512-472-TIPS.
This article originally appeared on Austin American-Statesman: 1991 Austin yogurt shop murders case unresolved as anniversary looms