The first step to the examination of the anonymous letter consists in procuring as many suspects as possible, which, as before advised, should be lettered or numbered and put aside, until the original, which in this case is the anonymous letter, has been studied and mastered. The external evidence of which so much has already been said may or may not be looked for.
Next proceed with the examination and comparison of the writings. It is presumed that the student has prepared his notes of the peculiarities of the original; he has now to search for them in the suspects. Suppose he begins with the spurs and beards, having found them well marked in the original. He will take any one of the suspects and examine it for a repetition of the same signs. He may follow on with the rest of the suspects, taking advantage of his memory being fresh on this point, or he may prefer to exhaust one suspect of all its evidences before proceeding with another; but practice and experience will decide the best course in this matter, and influence the line of procedure.
Whatever method is pursued, all have the same object—the discovery of the peculiarities of the original in one or more of the suspects, and the student will be wise if he follow accurately the course laid down in the chapter on "How to Examine a Writing."
It is generally safe to take it for granted that the writing in an anonymous letter is disguised. There are occasions when the author persuades another person to write for him, but only rarely; for the perpetrator of a contemptible act is not usually brazen and indiscreet enough to expose himself to others. The same reasons lend strength to the presumption that the writing will, so far as its general appearance goes, be as much the opposite of the author's usual style as his ingenuity can make it. The extreme back hand occurs very frequently. It seems to be the first impulse of the anonymous writer to avoid the right slope. Even when the normal hand is a vertical, with a tendency to back hand, the extreme left slope is often chosen. Fortunately, the assumed back hand is one of the most transparent of disguises. If the student has practised it, he will not need to be reminded how difficult it is for a writer to conceal his mannerisms. By altering the slope he has only stretched and lengthened his outlines, and the expert soon learns to recognise them in their new form.
Another common disguise is the illiterate hand. This is quite as easy of detection. It is no easier for the practised and fluent writer to reproduce the shaky, irregular outlines of the illiterate, than it is for the speaker of pure and cultured English to imitate the coarse accent of the vulgar. However good the copy it always breaks down early, and the sudden and unconscious firm, clear and geometrically accurate stroke reveals the practised writer beneath the mask. Sometimes an accurately placed punctuation mark supplies the necessary clue, for when once the art of proper punctuation has been acquired it becomes almost automatic. Even experienced novelists are caught this way occasionally. They will introduce a letter, supposed to be the work of an illiterate character. The grammar and orthography suggest the idea, but the more difficult details of punctuation will be attended to, even to the apostrophe that marks the elided g in such words as "talkin'," "comin'," &c.
Very difficult and troublesome is the letter written throughout in imitation printed characters. The expert has to rely upon the curved lines, accidental punctuation marks and unpremeditated flourishes and hand-gestures; but, broadly speaking, such a letter is beyond the skill of the expert if unaided by accidental betrayal. If, as sometimes happens, the writer is ingenious enough to adopt an alphabet formed completely of straight lines and angles—an easy task—he may boast of having produced a detection-proof writing; that is, if characters formed with the aid of a rule can be called writing, for it defies detection, because there are none of the signs essential for comparison, and is less easy of identification than an incomplete skeleton. In the absence of external clues, an expert would refuse to do more than offer a very guarded opinion, and it would be wiser to decline to offer any comment whatever.
Another trick that has been resorted to by some persons is writing with the hand constricted by a tight-fitting glove. This produces a very effective disguise; but if the student will practise with the same impediment, he will discover many useful rules for guiding him on the road to penetrating this entanglement.
It should be remembered that the less control a writer has over his pen, the more likely is he unintentionally to revert to those forms to which he is habituated, for, left by itself, the hand steers the more familiar course. Disguise, alteration and variation on customary forms are the result of premeditation. When the mind is occupied more with the subject than the formation of characters, the latter naturally assume that shape to which the force of custom has bent them.