Lawyers for Casey Anthony are trying to convince a judge that the mom suspected of killing her daughter Caylee was not properly read her rights and that key statements by Anthony should be thrown out of her upcoming trial.
Among the remarks that could be at risk are Anthony's statement to Florida police that her missing daughter was with a babysitter named Zenaida Gonzales. Police eventually determined that Anthony did not know a babysitter named Zenaida Gonzales.
Losing key testimony of this kind could make it difficult for prosecutors to get the conviction of first-degree murder -- and the death penalty -- that they are seeking.
Anthony's defense is also trying to rule out jailhouse videos and statements she made while in jail where she talked to her family and visitors in the days while Caylee was still listed as missing, but before her body was found.
ABC News' Dean Schabner and Emily Friedman contributed to this report. The Associated Press contributed to this report.