If it can be proved that Casey killed her child on purpose, she belongs in a mental institution. But if it was an accident, then perhaps it wasn't Casey's fault, but she's afraid to tell the truth.
Maybe it's me. It's hard for me to believe that a mother would deliberately kill her own child unless she has a severe mental illness.
Has Casey been examined by a good psychiatrist? A good psychiatrist can usually tell when a patient is lying. Otherwise, this incident reminds me of the film, The Bad Seed. This is about a child who kills and steals without any feeling of remorse. She seems to have 2 personalities. One sweet and nice with her parents, and another with her friends or anyone she suspects of knowing the truth about her. The child was adopted, and like the real mother, it is discovered in the film (book-play) that she too committed many crimes and eventually disappeared, leaving the baby alone. Was there any pathology in Cayce's ancestors? A grandmother, an aunt, a cousin, anyone? Also wondered if Cayce was adopted as an infant? Not heard anything about that.
I suppose you could argue that anyone capable of murdering a child has what the layman would consider a serious mental illness. Pedophiles do, too. As far as I know, neither can be rehabilitated to suddenly grow into a person who will no longer endanger children. Therefore psychological "help" would be of relatively little benefit for effecting change in the criminal or safety in society. Taking them out of society for life is therefore one of the two options (the other being death) that will suffice.
If Casey Anthony had an incurable genetic predisposition for murdering her child without remorse - or she has no genetic predisposition and just chose to do it because she's a bad person - the result was the same and her daughter is dead and now Casey is subject to the laws that govern us all, that she knew about before committing murder, that she gambled on when she took another human's life. She hid it, so she clearly knew it was wrong (and was not so mentally ill that she didn't know the difference), so she's subject to the punishment.
I feel the same way about Scott Peterson. I feel he left more evidence in the "motive" and "premeditation" categories than ICA - the clincher when he told Amber on December 9th that he lost his wife, then the same day purchased a boat that he used to get to his chosen dumping ground. I feel SP left an equal amount of damning evidence on his computer - ICA with the chloroform search, SP with the search for tides in the Bay off the Berkeley marina where Laci was ultimately found. I feel ICA left far, far more evidence of her proximity to her victim and possible method of death than SP did - the trunk, the yard, the bags, the tape. SP left the anchor imprints but no direct evidence of how he killed her (as far as I remember...)
Both continue to give character evidence in the form of their blank faces and missing emotional cues during key places in the testimony. ICA tries to act a little harder than SP, though she's not successful, IMO. Jurors commented on SP's cold stare. Afterward I will not be surprised if ICA jurors comment on the same thing.
However in the end I think it's perhaps easier to condemn a man to death than a young woman. Human nature? Like some new posters commented here, they can't imagine a mother killing her child (though it happens so much, intellectually we should all know it's more than just possible whether we want to imagine it or not) so if the jurors feel the same, I think ICA's jury will have slightly less inclination to sentence her to death.. also CA has become an incredibly sympathetic figure, and a victim in her own right, so sentencing her only daughter to death might feel like further victimization of the living victims - whereas SP's parents did NOT come off as sympathetic at all and it was hard to see them as victims of Scott in the slightest.