For years, criminals used women's hosiery as a mask to hide their identities.

But today, to a forensic scientist, hosiery can be as valuable as a fingerprint

because of its signature characteristics.

And textile science identified a killer when an eyewitness couldn't.

In the small Midwestern town of Heron, Illinois, murder was like a virtual stranger.

It's so rare that police thought this 911 call was a prank.

911 emergency.

There's been a rape and a murder at the drag train place.

We're a rape and a murder.

Can you tell me where to the body and everything's at?

It's in the back of the place.

You go through a door.

What is your name, sir?

I can't tell you.

You can't.

Police traced the call to a pay phone near the center of town.

Just up the street was a dry cleaning store.

The front door was open, and no one was there.

Behind the counter was a purse with its content scattered all over the floor.

Right at that moment's when we thought there's something serious here.

In the back room, behind a water heater,

police found a woman's body.

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