Lox, let me help you to comprehend the meaning of your Guardian quote.
"ok so they are concerned that the information they gathered was being "generalised to an entire crime type" "

It means that there is a recognised crime type here.
They have only studied a small number (17) of cases so the data should not be generalised to the whole of this (recognised) crime type.
That leaves open the possibility that these cases are indeed typical of this crime type.

More study of this (recognised) crime type is required to confirm that.
OK Lox?