'Black Widow' to Appeal Guilty Verdict

May 28, 2010— -- Stacey Castor, the widow who was convicted of murdering her husband by poisoning him with antifreeze and attempting to murder her daughter and frame her for the crime, will appeal the guilty verdict.

Castor's new appellate lawyer filed a motion in March, saying that a police interview with Castor, which contributed to her conviction, never should have happened because investigators knew she had a lawyer at the time, and that, as a result, information obtained in the interview should not have been allowed in court. No date has been set to argue the motion in court.

Castor, who is serving her 51 1/3-year-to-life sentence in a New York State prison, continues to deny any wrongdoing, insisting that she's innocent.

"I did not kill David Castor," she said in an exclusive interview with ABC News' David Muir last May. "And I did not try to kill my daughter, period. And I will never say that I did. Ever."

Castor stood before a judge and jury in January 2009 in the Onondaga County courthouse in Syracuse, N.Y., where she was given the chance to plead her innocence. Jurors listened to the testimony of more than 50 witnesses and deliberated for three days.

She was accused of murdering her second husband, David Castor, by poisoning him with antifreeze in 2005, and attempting to poison her daughter, Ashley Wallace, with a toxic cocktail of crushed pills and vodka. She also was suspected of murdering her first husband, whose grave lies next to Castor's.

"I think she's diabolical," assistant district attorney Christine Garvey said. "What she has done over the course of seven years is just unimaginable."

Castor's defense attorney, Charles Keller, said, "It's a tragedy for everybody. No matter how it comes out ... it's a tragedy. ... There is no happy ending."

Keller spent almost two years digging up a trail of evidence that, he said, pointed to a different murderer: Stacey Castor's then 21-year-old daughter, Ashley.

Stacey Castor alleged in court that her daughter had murdered both David Castor and Michael Wallace. If Ashley had indeed been responsible for Wallace's death, it would have meant that she killed her biological father by poisoning him with antifreeze at the age of 11.

"It may be easier for people to decide that I did it because I'm the mother," Stacey Castor said. "But kids do things like that. All you have to do is turn on the news or read the paper. There are children that kill children and other people every single day. It happens."

Castor hasn't spoken to either of her daughters since she was arrested at the hospital after Ashley Wallace nearly died in September 2007.

"You know, the truth will come out," Castor said. "I know that the truth is going to come out of this. The evidence will show that I am innocent. And I will go home."