I am, and will remain suspicious of the parents. Just consider what they are asking us all to believe.
They say they went out to socialise, while leaving the children alone. In addition, they left the appartment doors unlocked, so that anyone could walk into the rom where the children slept.
I do not believe anyone could be so grossly negligent.
Here is what I believe.
Madelline was killed before the parents went for their night out. But first they needed a plausible account for the childs disappearance. They decided on the kidnap story.
To make it look like a break in, would not be difficult, the difficulty would be fooling detectives. Bursting doors and windows not only attracts unwanted attention, it leaves forensic evidence.
Yes anyone can avoid leaving fingerprints, but what about microscopic evidence? like traces of fibres at the doors and windows. The police would then seek out clothing, and minutely examine the parents for similar fibres. The parents decided it would be better to not go that way.
Instead they invite us to believe their ridiculous story of a kidnapping and unlocked doors, and their fears of fire.
Something is very clear to me. Their explanation is a and bull story. More importantly, it is something any clever people could have improved upon with time and planning.
The murder of this child was not a planned thing then, it is consistent with one or both parents loosing their temper and doing serious harm to the toddler.
The parents then concoted their story.
The one thing they did do right was to not allow recovery of the body, for that would be damning. Head injuries are what I would expect to see on the body.
If the mother had accidentally poisoned the infantas has been claimed, I think she probably would have admitted it, and settled for the short term of imprisonment mooted. But she cant take that option, a confession would lead to demands for the body.She cant do that, the body would tell the truth, revealing the beating that led to the childs death.
I am sure the body will never be recovered. They are smart enough to have seen the need for this. The body was placed in the sea, or perhaps the lake discussed elsewhere. he sea would be a beter bet. As doctors they would know how to degrade a body quickly, it might be that a pit was dug and lined with cement powder and the child emplaced and covered in the material. This stuff is easilly obained from bilders merchants.
How they disposed of the body is not that important. The important thing is to get a confession, and for that we must wait for one of them to break.
I think Mr. McCann had a bigger part to play in this crime. When I look at him I see a man who owns a quick and nasty temper.