"She adds that, after having spoken to the McCann couple, she spoke to the resort manager, and after identifying herself, asked him whether there had been a break-in in the apartment where the child was, to which he replied no but that the door was open as were the window blinds, which, according to Kate, should have been closed but were found open."
I fully understand there were no signs of forced entry, so is that is what is meant by "break-in"?
What is the true definition of breaking and entry?
breaking and entering
v., n. entering a residence or other enclosed property through the slightest amount of force (even pushing open a door), without authorization. If there is intent to commit a crime, this is burglary. If there is no such intent, the breaking and entering alone is probably at least illegal trespass, which is a misdemeanor crime. (See: burglary, trespass).
https://www.justia.com/criminal/docs/uniform-crime-reporting-handbook/burglary.html"Burglary—Unlawful Entry—No Force
The entry of a structure in a Burglary—Unlawful Entry—No Force (5b) situation is achieved by use of an unlocked door or window. The element of trespass to the structure is essential in this category, which includes thefts from open garages, open warehouses, open or unlocked dwellings, and open or unlocked common basement areas in apartment houses where entry is achieved by other than the tenant who has lawful access."
So as soon as the burglar reaches inside he has unlawfully entered a building. There maybe no break-in just unlawful entry no force.