David Muir

And while doing so, they happen to trip over a body.

And that is when they discover a horrific scene.

Then they recognize it's two, and then three, and then finally four.

The yogurt shop, it's probably like a typical retail space in a strip mall.

You have the consumer area up front, tables and chairs, and there's a counter kind of in the middle, and then there's the back room where the storage and office and everything is.

I got there right after the fire had been knocked down.

Very smoky.

There was water dripping from the ceiling.

It was overwhelming.

Three of the girls were just totally not identifiable.

They were burned too much.

As soon as the Austin Police Department realized the scope of what they were dealing with, they called in extra investigators to help them.

Specifically, the FBI arrived at the scene, the ATF arrived at the scene.

It was an uphill battle to begin with, the processing of that crime scene.

Everything gets doused with water.

Because they did such a good job in putting the fire out, a lot of our evidence was destroyed.

There was evidence of sexual assault at the crime scene on the victims as well.

So all four girls were nude, and their clothing had been used to tie each other up.

They also took DNA from those victims.

So part of your standard sexual assault kit at an autopsy, besides swabs, is you also would take fingernail clippings.