Its ludicrous to think the window was used why? First off here we go again there was a bed DIRECTLY under it. So who would use it to go out? They would have to open the window with a child in the arms stand on the bed balance etc ....... it would leave DNA everywhere unless the guy was wearing a full on protective suit.
To open it from the outside didnt i read the other day that this particular blind cant be opened from the outside. It can be lifted up by about an inch but then the ratchet system stops it from being pushed up as you have to use the internal system to do that, a bit like a seat belt? Besides which they make a noise.
No I have always believed the child was taken out of the front door. Its easy and it makes sense.
Lets face it anyway, if someone is clever enough to drug 3 children, take one without any traces, or anyone seeing them, and the child is never found, then that same someone is cleverer enough to procure a key.