Texas' highest criminal court on Wednesday let stand a lower court ruling that threw out Andrea Yates' murder convictions for drowning her children in a bathtub in June 2001.
Harris County Assistant District Attorney Alan Curry said the case would be retried or a plea bargain considered.
Jurors rejected Yates insanity defense in 2002 and found her guilty of two capital murder charges for the deaths of three of her five children.
Curry said if the case goes back to trial, he is confident Yates would be convicted again. He said a plea bargain also may be discussed.
"Andrea Yates knew precisely what she was doing," Curry said. "She knew that it was wrong."
Yates' attorney, George Parnham told CNN that he hoped Yates belongs mental health facility, not behind bars.
"She has been told she will be retried," Parhnam said. "She doesn't want to go through this process. She is very concerned about it. The right thing needs to be done here."
The First Court of Appeals in Houston overturned Yates' 2002 convictions in January because of false testimony from forensic psychiatrist Park Dietz.