I think the kidnapping charge would indicate that there was some sort of confession/detailed information provided by either MH herself or someone closely associated with her. I realize we might be missing a lot of information, but nothing published, video or otherwise, would lead us to suspect kidnapping was involved. Kidnapping is not an inherent charge to murder, correct?
I can't believe that this was an accident, because just like Caylee, if it was an accident why not to confess to it when the poopy hits the fan? The idea that a murder charge is preferable to a heartfelt, tear-sodden "I didn't mean to run her over/leave the pool gate open/confuse the antifreeze with Koolaid" is just unfathomable. Maybe if evidence comes out that MH tied poor Sandra up before accidentally backing over her in a SUV, I'll change my tune.
I like to give people the benefit of the doubt, but in this case an accident theory would seem farfetched. She told them something about the crime that led them to the kidnapping charge.
Could it be possible that Sandra was alive in that suitcase when she was loaded in the car and suffocated before MH's true intentions could be revealed? Whether it be sexual in nature, or whatever else. I hate to think she was drowned alive like a callous person does to a puppy, but the "waterproof" nature of the suitcase really scares me. Non-breathable fabric. A lined, sealed suitcase dropped in a pond.
Still doesn't speak to motive, though.