You're not the only person who wonders this. Add to this, why would she even stay in town? (and why would she drive around with the body in the trunk if she
knew it was there, rather than dispose of it immediately, etc.)
The location and method of disposal to me seem exculpatory. If KC were the murderer she would have no reason to leave the body in that location, every reason to dump it anywhere else. She would have no reason to leave the tape on, and every reason to remove it before disposing of the body. No reason obviously to leave all the other items that would link back to her family home or herself. It's not impossible but just very hard to believe. If KC were subnormal in intelligence, maybe, but she's not, and she would not want to go to prison for life or face the death penalty. I can't rule KC out, but another perpetrator could obviously have obtained these items in a number of ways, whether from a bag of KC's or Caylee's, from the car, from a sitter's place or someplace KC had been staying, even directly from the A home if the perp is someone who had access or gained access somehow.
Re: crime scene, we have next to no info beyond KC's trunk or the backyard, since the cadaver dogs were only used there, etc. I think luminol (or "bluestar" or whatever the brand was here) was used in Caylee and KC's bedrooms at the A house, right? At least no bloody crime committed there, smothering or other bloodless death possible if no body fluids were deposited as a result. The fact that no one or their dogs in the neighborhood smelled or came across the body by the side of Suburban in June or July, and it wasn't found in any searches, even with so many people converging on that neighborhood, adds to the suspicion that it was moved there later, by whatever perpetrator, the doublebagging may have been for this reason. Definitely wish there was more info re: crime scene. I voted "someplace else" but can't rule out one or two of the other choices. Thanks for the poll, HP