[Moriarty claps his hands sharply, in order to get everyone's attention, before smiling calmly.]

Now then! If all of you would be so kind as to write down the passages on our two notes and hand them to me, I will compare them to both your samples and to each other. I will, of course, write my own - which I would ask to be reasonably verified by someone else.

[So, he'll essentially be comparing the handwriting of both notes to each other, and then each note to each handwriting sample given by everyone who can at trial.]