Anne-Marie Green

That is when they zero in on John Kogan.

He's a 21-year-old landscaper.

Detectives say that he dated Kelly for about a week or so.

And in the course of your reporting, I'm curious about whether you learned anything else about him.

Well, that is what struck me about this confession, the remarkable level of detail.

And so you can't help but to think, who would make this up?

John Kogut, Dennis Halstead, and then John Restivo, they're all charged with Teresa's murder.

All three of them plead not guilty.

But then at trial, police also testified that they recovered two hairs

belonging to Teresa in Restivo's van.

And then, of course, they testify about Kogut's detailed confession.

All three men, Kogut, Halstead, and Restivo, they were all convicted, and they were sentenced to more than 30 years to life.

But then nearly 19 years after Teresa was killed, there was a stunning twist in the case because of advances in DNA technology.

We saw it in The Hour.

What more can you tell us about how that unfolded?

This reminded me when I watched it of a case that I worked on for 48 hours a while back.

It was one of the first ones I ever did.

It was about the murder of Angie Dodge.

This is in Idaho Falls in 1996.

She was an 18-year-old.