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.

Inside the yogurt shop were the char