In a sense, there is indeed such a thing as a 'lawful killing'.. self defense.. perhaps little Caylee was threatening her mother with a lollypop or a rubber ducky or something?
Anyway.. I am not as convinced as I wish I were that this is an open and shut case. There is no one single piece of evidence, (so far released) that taken by itself, really shows that this was murder, and/or that KC was responsible. Taken all together, the evidence seems overwhelming, and I cannot imagine what the defense will be, but juries do not always listen to the whole chain of evidence. They wait to hear that 'her fingerprints were on the duct tape.' If it isn't as simple as that, they hesitate to convict a pretty young woman on circumstantial evidence alone.