I'm Lester Holt, tonight on Date Line, a mystery in paradise.

A young woman murdered near the white sands of Jacksonville Beach.

I would play out possibilities of what happened that night.

I thought about how scared she must have been.

You could tell that she had thought for her life.

You can see what almost look like handprints coming out the window.

And those were in blood.

People were scared.

Women who lived alone were scared.

Neighbors were scared.

Was your gut telling you that this was someone she knew?

Yes.

Everybody became a suspect.

You know you were a suspect, mother?

How long have those exist?

He pointed down to Cory's window and said,

I watched that girl down there.

Are you starting to think she could be Cory's killer?

She was a person of interest, definitely.

How are you feelings?

I mean, this is a murder investigation.

Bullied. Help us.

...