A very big difference between Andrea Yates, Susan Smith, and Casey is that Casey and Caylee lived with the family. It is often harder to see changes in people that live under the same roof. I would think that it would also be harder to accept that someone who shared your home would be capable of murder.
Another difference with Yates is that it was known to her family that she wanted to get help but her husband didn't think that she needed it.
I agree these are not cases on point. Cases on point, however, generally aren't so high profile that many would recognize their names. Another difference is that in the named cases, there wasn't a history of lying, stealing, etc., to the best of my knowledge. With the Yates case, yes, the family was aware of her mental health issues, but in this case, Cindy herself described Casey as a psychopath. Cindy herself threatened to take custody from this, "mother of the year." Cindy herself sought psychological help in dealing with
Casey.
You suggest there were changes in Casey that occurred subtly over a period of time that were hard to perceive by those closest to her.
My understanding of the situation is the exact opposite. Per Lee, Cindy's first words upon seeing Casey crying were, 'What have you done!?!' This is not someone in the dark about who and what her daughter is. Almost all closest to her described Casey as a liar and a thief. JG went so far as to say she was a 'diabolical liar.' Even if this wasn't the case, what to do when confronted by LE with all the lies? There is no nanny; there is no job; there was no trip to Jacksonville; and on and on and on. What then? Blithely continue on as if one never heard it?
Also about living under the same roof, that's something that cuts the other way pretty hard too --- Caylee wasn't under that roof for a month. Wouldn't that constitute something pretty dramatic that even the most nonattentive would notice? Cindy seemed to notice it pretty well in her myspace post.
Back to my point, which was that in most instances, these cases rarely make national news. How many times have we all heard on our local news about a parent or stepparent being accused in the death of child but never saw the actions from those families that we've seen in this case? Didn't the Smith case start out as a "missing" case? Haven't there been lots of others over the years? IMO, the grandparents' media mystery tour fanned the flames on this one, while at the same time, other families chose to accept the obvious, deal with their pain privately and let the system take its course. I'll venture a guess that in most of those cases, especially when the child lived under the same roof, 31 days didn't go by without reporting the disappearance.
I've been harping on it all night but I'll mention it again: The persistent lying of the grandparents that was so pernicious on the part of Cindy that LE asked her to stop because it was hurting the investigation; that was so transparent that George apologized to LE and said something to the effect of he'd tried to put his hand over her mouth. Riddle me that one, Batman. It makes no sense. But for the actions of the grandparents, I think this case would have remained a local case, a blip on local news and forgotten. There would not likely be a dream team or private attorney. Instead, as in other cases, there would more likely have been a public defender and a plea within a few weeks, imo. But no, we now have what I believe is an orchestrated media extravaganza, with the grands playing their part at a great cost to the taxpayers and it appears, potentially an even greater cost to George. And to what end? I have to agree with Turbothink's sig line about Cindy spitting on Caylee's grave.
Something else for which I'll never forgive them, while they were out there trying to act as ringmasters for this circus, numerous other children were legitimately lost/kidnapped and have not yet been found. IMO, they personally are responsible for not only the backlash they received, but consequences that will paid by others because of their behavior. The families of other victims will many times be treated with more skepticism and less willingness to help because of these two people, at least by me and several others with whom I'm acquainted.