"I didn't know that he was going to say that. We had talked about all aspects of it, and I did not know. I don't know if anybody knew that he was going to say that other than himself," Mason recalled.
I asked Mason if he was concerned the defense would not be able to establish this with evidence as promised during the opening statement. Mason said he was.
"Yes, I was concerned about that because I knew we didn't have the ability to prove that unless George got on the stand and confessed," he said.
The prosecution responded by making George Anthony its first witness. The first question Assistant State Attorney Jeff Ashton asked him was whether he had sexually abused his daughter. George Anthony responded with a definitive no.
The trial went on for weeks. Witness after witness took the stand for the prosecution in the largely circumstantial case. They finally rested their case on June 15, 2011. Then it was the defense's turn.
Anthony's defense attorneys maintained that Caylee was not murdered at all. They said the child drowned in the Anthony's above-ground pool, and that Casey Anthony and her father panicked upon finding her there and covered up the death. George Anthony denied that in his testimony.
In the midst of the defense case, Mason described how out-of-court conversations with the prosecution suddenly turned to possible plea discussions. Anthony was approached with the possibility.
"Casey got very angry about that. She got very angry to hear talk about it. She didn't want to hear it." Mason said. "Casey would fight it 'til her last breath. She didn't kill her daughter."
Mason said he believes it took a lot of courage and strength for Anthony to end any talk of a plea agreement. She knew what was at stake in this death penalty trial.
So, plea discussions were stopped in their tracks, Mason said, and the trial went on.
Then, on July 5, 2011, after deliberating for 10 hours, jurors announced they had reached a verdict.
"She was holding her breath like a deep sea diver, waiting as we all were," Mason said.
Anthony was acquitted by the 12-person jury on the most serious charges, including first-degree murder, aggravated child abuse and aggravated manslaughter of a child. But the jury convicted her on four misdemeanors of providing false information to law enforcement officers.
Anthony now lives in an undisclosed location in Florida and doesn't go out of the home she is living in because of the public hate and continued threats to her life, Mason said.
"She has to live constantly on guard. She can't go out in public," Mason said.
By her own choice, she works inside the home, Mason said, and is living as "a housekeeper, clerk, secretary and stuff like that."
"I think Casey has a lot of world left to have to deal with. She hasn't been freed from her incarceration yet 'cause she can't go out. She can't go to a beauty parlor, she can't go shopping to a department store, she can't go to a restaurant, she can't even go to McDonald's. She can't do anything," he said.
Mason and his wife, Shirley, have continued a relationship with Anthony. Now three years after being acquitted, Mason said Anthony still distrusts the outside world.
"Casey is aloof," Mason said. "She is kind of, I think, afraid of people ... she's not real close to. We've had a couple of occasions to have social gatherings that can include her -- close friends, the (legal) team. She still likes to back away from the middle."
Anthony "does not have any blood family anymore," Mason said. The family she has is the residual of the defense team, Dorothy Clay Sims, Lisabeth Fryer and Mason's wife.
Mason said although there may have been a few conversations between Anthony and her mother in recent years, there is no relationship.
And as for a relationship with her father? "None," Mason said emphatically.
Shirley Mason has also gotten to know Anthony over the past three years.
"I'm a cross between a friend, a mother, but not a mother -- only someone who is older who has had experience in the world she has not had," she said.
Mason gives Anthony advice, but also listens to her when they talk.