Four teenage girls were killed at a yogurt shop in Austin, Texas, more than 30 years ago. Their deaths have never been solved. Before new DNA evidence made it less likely that the first people arrested were involved, they were arrested and convicted, but those convictions were later overturned on appeal.

Investigators have reached what seems to be a dead end in the case, but there is a theory that two men who were seen in the yogurt store the night of the murders may have been involved in the unsolved killings that have plagued Austin for decades, as “48 Hours” correspondent Erin Moriarty reported this week.

Inside the yogurt shop, the burned bodies of four young girls, ages 13 to 17, were found. Starting from the top left, the victims were Jennifer Harbison, who worked at the yogurt shop with Eliza Thomas, Sarah, Jennifer Harbison’s younger sister, and Amy Ayers, who was a friend of Sarah’s. Sarah and Amy went into the yogurt shop right before it closed on the night of the killings. All four of the women had been shot, tied up, and put on gags.

On December 6, 1991, Eliza Thomas, 17, Amy Ayers, 13, Jennifer Harbison, 17, and Sarah Harbison, 15, were tied up in a “I Can’t Believe It’s Yogurt!” store in Austin, Texas, when they were shot in the head.

It was a crime that the city had never seen before. Eliza and Jennifer had both worked at the yogurt business that night. As they were about to leave to go home, Sarah, Jennifer’s sister, and Amy,…