Yeah, I had thought maybe this was part of a strategy to pressure Casey...not to do anything to show their hand as to what they've found out about her movements or what they don't know by not doing anything that would be covered by the media, e.g. if they're searching lakes and swamps and she did something totally opposite then she would know they had no solid leads.
But, I can't see police not trying to find the body of a 3 year old if they had any clue where to start looking.
Lastly, while almost everyone on this board thinks Casey killed her daughter, right now, there is no body, no crime scene, we don't know what the foreniscs will find about the car/hair/stain, etc. a 'dead body smell' that has now been recanted into pizza/detergent isn't much evidence...
If forensics come up inconclusive and for whatever reason Casey's movements are hard to track..paid cash, stayed with criminals...and Caylee's body isn't found it is going to be VERY hard to make a case stick.
At this point, if no physical or other evidence is found Casey is free to make up whatever story she wants of babysitters/cult members/one armed men/the mob/drug dealers who stole her baby and there will be nothing to prove it isn't true. LE is in a pretty tough spot right now..a strong theory of the case and not much factual evidence.