For anyone unfamiliar with the case, here's the evidence in a nutshell:
The evidence was more than sufficient to prove a homicide: a baby disappeared and the last person seen with the child—the mother—lied repeatedly for a full month about her whereabouts; deliberately lied in a way that prevented anyone from searching for the child. The mother's researching of chloroform on the computer matched up to the finding of chloroform traces in the trunk of the car. The same car trunk where a hair consistent with Caylee's was found; a hair that was arguably from a decomposing body. The same car trunk from which the smell of a decomposing body emanated strongly. The child's decomposed body was found bagged in the woods near the mother's house. Significantly, the child's mouth and nose had been duct taped. And while that child's body lay decomposing in the woods, the mother euphorically and gleefully partied with her buddies knowing full well that not only was her child dead but she was actively preventing anyone from finding out. That evidence not only proved a homicide, it proved that Casey Anthony committed it.
Casey's behavior was "bizarre"? No. Casey's behavior was INSIDIOUS.
http://powerwall.msnbc.msn.com/politics/casey-jury-brainwash-1694371.story