Entertainment Tonight ET Online ETOnline.com

Casey Anthony has been in hiding since she was acquitted of murder last July, but she resurfaced on Tuesday for an untelevised phone conversation with Piers Morgan.

"I didn't kill my daughter," Anthony pleaded, according to excerpts read by Morgan. "But I'm ashamed of the person that I was."

Last year, Anthony was prosecuted for the death of her two-year-old daughter Caylee in a lengthy trial that captivated the nation. Prosecutors argued in closing arguments that Anthony killed her daughter in June 2008 by putting duct tape over her mouth because the toddler interfered with her partying lifestyle and love life.

RELATED: Rob Lowe to Star in Prosecuting Casey Anthony

"I was a stupid kid," Anthony admitted. "But I've never been a 'party girl'... and I've gone through hell."

During the trial, Anthony's attorney contended that Caylee drowned in the family's pool but that Anthony's father panicked and decided to make the death look like a homicide by putting duct tape over her mouth and dumping the body in the woods. Her father, George Anthony, denied any involvement in Caylee's death or disposing of the body.

The 26-year-old is currently serving probation on a check-fraud conviction.

Tonight, Anthony's lawyer J. Cheney Mason appears live in the studio for an interview on Piers Morgan Tonight, airing at 9 ET on CNN.