One of the reasons that led to the overturned conviction was a jailhouse witness who recanted her testimony about Arnold confessing to killing her daughter. Paris Talley was 28 days old when she was killed in 2005.
Prosecutor Dan Brandt said, "She was cooked to death in a microwave oven."
Who put the baby there is back up for debate in the third trial. Prosecutors said it was Arnold and they said she had told many different versions of what happened.
Brandt said, "She tells her first story. By now she's got another story. She claims she was too drunk to remember anything. You'll learn that that story will change, too."
According to prosecutors, even though one jailhouse inmate recanted her testimony, they have other witnesses.
"The defendant made statements to fellow inmates in the jail regarding her responsibility for the murder of baby," said Brandt.
Defense attorney Jon Paul Rion said he believes, this time, a jury will find reasonable doubt. Since the baby's death in 2005, Arnold has been accused of being the killer.
"What you have heard is not true," said Rion. "Her own daughter Paris, was murdered or killed, but not by China."
Rion said witnesses will testify that they saw other people in Arnold's apartment during the time Paris died in the microwave oven. They also plan to prove that her alleged confession the day of the death, was taken out of context.
"If you hear it in context, China didn't know if she rolled on her baby. She didn't know how her baby died," said Rion.
Rion said he also has jailhouse witnesses and said, "There is a counter person or two or three or many, to each of those statements."
The trial is expected to last two weeks.