Tonight on Dateline.

The Ann's dad called me in, told me Ann was dead.

Look down the basement, could clearly see somebody's legs.

Kara says, I don't know, maybe she fell down the stairs.

I had nightmares for months.

There was paint all over the place.

One of the most odd scenarios I could have ever dreamed of.

What do you make of the paint to cover up?

As simple as that.

Things were moved before we got here.

This isn't what it's made out to be.

I know they had their problems.

I think every relationship struggles.

Anna Marie was a big spender.

She owed other people money. It was a big spender. She owed other people money.

It was a relationship of extremes, hot, cold, wild, calm.

There was a guy named Mark.

He was a married man.

Clearly there was an emotional affair between Mark and

at a minimum.

When buttons are pushed, people get angry, people get upset.

A history-making case, and now after four trials,

...