We know without a doubt WHO that child was with when she went missing. Casey herself told investigators the date that 'Zanny' the 'nanny' did in the baby. (I have since learned that 'Zanny' for some is code for meds given to little ones who need to sleep while the adults party.) We know that Cindy was hunting Casey and Caylee by the 911 call made 31 days later. And there is NO doubt that Casey would not have waited until trial IF there was one shred of evidence to demonstrate that it was NOT her who killed and disposed of the body. She was offered two times a deal before the body was ever found to tell investigators where the body was. She could have turned in her father at that very time and already been out of jail if that claim had any veracity.
Is she dead yes, but how?
Those thing must be proved and the person who is responsible must be shown...in this case it was not.
It's our system, and no it is not perfect, but I wouldn't want it any other way.