Casey Anthony’s murder trial started Tuesday with a defense claim that her 2-year-old daughter Caylee died of an accidental drowning, and was not murdered, and that her mother lied about it.

“She was not ever missing and drowned in the family pool,” Casey’s defense attorney Jose Baez told the court in opening statements in a Orlando courtroom.

It was the first time Casey’s side had presented in detail her version of events in the sensational case that started out as a gripping missing child investigation before turning to allegations of murder by the child’s own mother.

Caylee had been reported missing in July 2008 and was found dead five months later, her remains lying in a wooded area less than a half mile from her Orlando home. By then, Casey, who hadn’t reported Caylee’s disappearance for a month, had already been arrested.

Casey’s attorney acknowledged that the mother didn’t tell the truth about the girl’s disappearance, making up the story about a nanny who had been the last person with Caylee, but claims there was a reason.

Casey, her lawyer said, had been sexually abused by her father, accounting for her unusual behavior.

“You will hear stories about a family that is incredibly dysfunctional, you will hear about ugly things, secret things, things that people don’t speak about,” Baez said.