Susan Spencer (48 Hours correspondent)

And yes, he did that after she had...

Skipped work one day.

Go through her room, looking for things.

He would look for cigarettes.

He didn't like her smoking.

In the months leading up to the killing, Joni kept a diary, chronicling Mindy's misbehavior.

Yet in all those years, Joni says, she only saw Andy lose his temper once.

And as far as emotional abuse, in terms of calling her names, belittling her, telling her she was worth nothing?

That was not true.

As for any sexual abuse... Did she tell you any of that?

Joni, your testimony in this is so important because there were just the two of you in that house.

Right.

The jury is going to look at this and determine that one or the other of you is lying.

It was Joni who walked in on a distraught Mindy that night.

She says her first thought was to get the gun out of Mindy's hand.

Andy's body lay just a few feet away.

Did you realize he was dead?

She finally got Mindy into the car, unarmed, and drove to the sheriff's department, where Mindy tearfully confessed.

The next day, Ruby Bereni did something perhaps only a mother could do.

It was the last thing I could do for him.