Chapter 18 — Exercises

Work these without looking back at the chapter first; then check yourself. Items marked † have full worked solutions in the answers appendix. There are no answers in this file. The mix is recall, applied reasoning, evidence interpretation, "spot the overstatement," ethics, and a cold-case extension. Keep asking the book's question of every item: what kind of claim is this, and how do we know it is true?

A. Recall and definitions

  1. Define a questioned document in one sentence, and explain why the paper, ink, and indentations count as part of "the document" just as much as the words written on it.

  2. List the cluster of questions a document examiner is actually asked (authorship, authenticity, alteration, sequence/dating, hidden writing, source of the medium). For each, state in a phrase whether the method that answers it sits toward the strong or the contested end of the validity spectrum.

  3. † Distinguish a collected (non-request) exemplar from a requested (dictated) exemplar. State the chief virtue and the chief peril of each.

  4. Define handwriting comparison, and name the two things it can do reasonably well and the one thing it cannot honestly do at the strength its courtroom history claimed.

  5. Define indented writing and the ESDA. In one sentence each, say what the ESDA recovers and what it cannot tell you.

  6. Define forgery, and name the four recognized categories of forged or disputed signature (traced, simulated/freehand, disguised, spurious/blind). Which one makes no attempt to imitate the genuine hand?

  7. What is a forensic document examiner (FDE), and how does an FDE differ from a graphologist? Why does that boundary matter in a courtroom?

  8. Name three line-quality features that tend to betray a slowly drawn forgery, and explain why "line quality" reveals the process of writing rather than its mere appearance.

B. Applied reasoning

  1. † An examiner is handed a single genuine signature and one questioned signature and asked, "same writer?" Explain, using natural variation, why one genuine exemplar is not enough — and roughly what the examiner needs instead.

  2. A forger produces a signature that matches the shape of the genuine one almost perfectly. Explain the paradox by which this can make it a worse forgery, not a better one, and name the feature that gives it away.

  3. A contract reads "$95,000," but the "9" sits crowded against the comma and is slightly darker under ordinary light. List four distinct physical tells an examiner would look for to decide whether the figure was *altered* from an original "$9,500."

  4. † A "1935" letter is written in a ballpoint ink that (suppose) was not manufactured until after World War II. State precisely what this establishes and what it does not establish about the document's date. Why is this a no-earlier-than boundary rather than a precise date?

  5. Two ink lines cross on a check — a signature line and a printed amount line. Explain what an examiner is trying to determine from the crossing, why it can matter to a case, and why the honest answer is often "indeterminate."

  6. A multi-page will is contested. List three physical features an examiner would compare across the pages to detect a possible page substitution, and say which earlier-chapter principle (about batches of manufactured material) the paper comparison borrows.

  7. Explain why recovering content with the ESDA is more scientifically defensible than concluding who wrote the recovered text. Which §18.2–18.3 problem reappears the moment you ask "whose hand?"

  8. An investigator finds a notepad at a scene, writes three lines of their own notes on the top sheet to log the find, then sends the pad to the lab. State specifically what the investigator may have destroyed and the one-sentence evidence-handling rule that should have prevented it.

C. Evidence interpretation

  1. † Re-read Figure 18.1 ("Fluent writing vs. a drawn forgery"). List the four tells the figure assigns to the drawn (simulated) sample, and for each, state the honest conclusion it supports — and the conclusion it does not support.

  2. Re-read the Figure 18.3 "Read the Evidence" block on the Lindbergh ransom-note comparison. Write, in your own words, the single sentence in its THE INFERENCE field at its true strength, and contrast it with the absolute sentence the original examiners gave.

  3. An examiner darkens the room, switches to infrared, and an added "9" appears as a black mark in a field where the surrounding ink has gone invisible. Explain why this is close to demonstrative evidence a jury can verify with its own eyes, and what physical fact about the two inks makes it work.

  4. A report states: "The questioned signature exhibits tremor, pen lifts, and blunt, even pressure throughout." Identify the one conclusion this best supports and the two conclusions it does not support. State the honest verb.

  5. An examiner reports that a contested signature "shows features consistent with the known writer and cannot be eliminated as the author." Identify three ways this sentence is appropriately honest about the method's limits.

D. Spot the overstatement / junk-science alert

  1. † A prosecutor's slide reads: "Handwriting analysis proves the defendant, and no one else, wrote this note." Name two distinct problems with this statement and rewrite it at a strength the method can bear.

  2. An "expert" testifies that, from the handwriting alone, the writer of a threatening letter was "anxious, controlling, and prone to violence." Name the pseudoscience being smuggled in, state plainly why it has no place in a courtroom, and explain how it differs from legitimate forensic document examination.

  3. A chemist testifies, from a destructive ink-aging analysis, that a contested signature "was placed on the document no more than eighteen months before examination." List three things a careful attorney (or juror) should probe before accepting that claim, drawing on §18.4.

  4. A detective says, "The ink-dating expert proved the will was back-dated, so it's a fake." Drawing on this chapter and on the prosecutor's-fallacy habit from Chapter 9, name two things to be skeptical of in that single sentence.

  5. A television examiner glances at two signatures for three seconds and announces "same hand, no question." Using §18.2–18.3, give two reasons this is backward from how a careful comparison actually proceeds.

E. Ethics and reasoning

  1. † An examiner receives a threatening letter together with a folder of exemplars labeled "suspect," plus a note that the suspect "has a clear motive." Using the Cognitive-Bias Watch in §18.3 (and previewing Chapter 31), explain the bias risk and the safeguard. Is an authorship comparison done blind worth more or less than one done knowing the suspect — even if the two happen to agree?

  2. Requested exemplars are taken from a suspect after arrest, by dictation. Explain two distinct ways this procedure can be abused or can mislead, and what good practice requires to keep dictated exemplars trustworthy.

  3. You are asked to testify that handwriting comparison "individualizes" a writer the way DNA individualizes a person. Explain why you should decline, and exactly what you can honestly say instead.

  4. A court adopts the "middle path" — letting an examiner point out similarities and differences between questioned and known writing but barring the ultimate opinion that a specific person was the author. Explain why this compromise is a fair mirror of the underlying science.

  5. Two qualified examiners reach different conclusions about a disputed signature, but both stop short of individualization and both report "inconclusive" or "consistent with." Is this a scandal, or is it consistent with how the method works? Explain.

F. Synthesis and validity spectrum

  1. † Place these four document-examination tasks on the NAS 2009 / PCAST 2016 validity spectrum (strong → contested), justifying each: dating an ink alteration by infrared imaging; recovering indented writing with the ESDA; determining stroke sequence at a line crossing; concluding that a specific person wrote a ransom note. Why are tasks from a single discipline so far apart?

  2. Explain how this chapter's split — a strong physical-evidence half and a contested authorship half — echoes the same pattern the book found in odontology (Chapter 17): a valid identification function and a discredited or contested comparison function in one specialty.

  3. In one paragraph, explain how this chapter advances at least two of the book's four themes (exclusion over proof; the validity spectrum; cognitive bias; the CSI effect cutting both ways). Name which themes and how.

G. Cold-case extension

  1. † Cold Case. Using only what the charred insurance/partnership document and its recovered indented writing establish (§18.5 and the Case File), write the entry you would add to the Mill Creek evidence log (Appendix I). State (a) the defensible inference at its true strength, (b) the honest verb, (c) at least three things this evidence specifically does not establish, and (d) why you decline to name who altered the beneficiary designation at this stage.

  2. Cold Case extension. A charred document gives an examiner less to work with, not more. Explain two specific ways fire damage degrades both the handwriting comparison and the ink/alteration analysis — and why this makes the "altered beneficiary" finding an indicated, not a proven, tampering.

  3. Cold Case, integrative. The document evidence supplies, for the first time, a documentary hint of motive. Name two other evidence types from earlier chapters that, combined with an altered beneficiary, would begin to connect a person to that motive — and state plainly why the altered document alone cannot make that leap.

H. Short writing

  1. In 150–200 words, explain to a juror why "the examiner saw an alteration under infrared" and "the examiner says the defendant wrote it" are claims of very different strength, and how to tell which kind of claim an examiner is making.

  2. † In 150–200 words, contrast the validity foundations of indented-writing recovery (ESDA) with those of handwriting-authorship comparison: what does each rest on, where is each strong, and where is each most easily overstated in court? Use the chapter's framing that one discipline wears two coats.

  3. In 150–200 words, explain why the Lindbergh ransom-note examination is the chapter's ideal closing case: name the genuine strengths the document work showed and the specific overreach it committed, and say what a modern, bias-aware examiner would do differently.