That is why the police suspected the parents/family. It almost has to be someone who knows them.
Else, how do you pick up some random person in Thailand? It's either family, someone known to the family, or a very resourceful stalker. Someone known to the police for other reasons.
additionally, although they didnt want to take chances in front of a jury on the matter, several hand-writing experts were prepared to testify that it was undoubtedly patsy's handwriting. furhtermore, the ransom note was made on a tablet of paper from within the house, and written inside the house. one page not used contained the beginnings of a letter, a straight line up and down as if to make an M or whatever. but the pen used to write the note was carefully placed back in the pen holding cup, if i recall. the big question being: why would a small foriegn faction wait until they had actually entered the house and abducted the girl before writing the note? isnt that a risky place to write a ransom note? the lead investigator wrote a book where he opined that jon benet wet the bed, and patsy freaked on her, and was coursely wiping her private area, perhaps while jon benet was standing on the edge of the tub, when jon benet lost her footing and hit her head on the tub. the rest, according to the investigator, was all staged. thus the same clothes the next morning, the note, etc. the investigator further concluded that john ramsey actually did find the body by surprise and put two and two together while being interogated by the cops, but didnt say anything.