1. Unit 7: Questioned Documents and Chromatography
Forensic Science
Unit 7: Questioned Documents and Chromatography

2. Evidence
1. Class characteristic—ink analysis, paper analysis, most handwriting analysis
2. Individual characteristic--With document analysis, it is difficult to identify to an individual characteristic except with typewriter or printer specific marks.

3. Questioned Documents
Involves the examination of handwriting, ink, paper, etc. to ascertain the source or authenticity or detect any changes.
Examples include letters, checks, licenses, contracts, wills, passports, suicide notes, receipts, etc.
Topics
Handwriting analysis
Ink (and pens)
Paper (and pencils)
Forgery
Codes and Ciphers

4. Questioned Documents
Forensic Document Examiner--involves the analysis and comparison of questioned documents with known material (exemplar) in order to identify whenever possible, the author or origin of the questioned document.
Unfortunately, no federal licensing exists.
May also be asked to determine if changes have been made.
Graphologist--attempts to predict character traits (personality) from handwriting examination

5. History
Led to the conviction (and execution) of Bruno Hauptmann in 1930 based on ransom note handwriting.
Has not always been accepted by the courts.
In 1999, the US Court of Appeals determined that handwriting analysis qualifies as “expert testimony” and is admissible provided it follows scientific guidelines.

7. Handwriting
Everyone has a unique handwriting style despite variations that occur due to mood, age, and hurriedness.
Handwriting analysis involves two phases:
The hardware--ink, paper, pens, pencils, typewriter, printers
Visual examination
Most frequently requested type of document analysis
There are 12 characteristics that are commonly examined. (RM pages 33-35)

8. Line quality
Line quality—do the letter flow or are they deliberate

9. Spacing
Spacing of words or letters—what is the average space

10. Size Consistency
Ratio of height, width, and size of the letters—are they consistent

11. Continuous
Lifting pen—does the author lift his pen between words

12. Connecting letters
Connecting strokes—how are capital letters connected to lowercase letters

13. Line habits
Strokes to begin and end—where do they letters begin and end on the page

14. Pen Pressure
Pen pressure—how much pressure is applied on the up and down stroke

15. Slant
Slant—do the letters slant left or right or variable

16. Letters Complete
Are letters completely formed?

17. Cursive or Printed
Are letters cursive, printed, or both

18. Fancy curls or Loops
Fancy writing habits—unusual loops or curls; unique styles

19. Diacritics
Placement of diacritics—crossing t’s and dotting i’s

20. Handwriting Analysis
Goal is to detect forgeries (documents made, adapted, or falsified in an attempt to deceive someone)
“ACE”
Analysis of the “knowns” with a determination of the characteristics found in the known .
Exemplars (letters, diaries, cards, personal notes)
Analysis of the questioned or unknown writing and determination of its characteristics
Comparison of the questioned writing with the known writing.
Evaluation of the evidence, including the similarities and dissimilarities between the “questioned” and “known” writing.

21. Obtaining Handwriting Samples
The subject should not be shown the questioned document.
The subject is not told how to spell words or use punctuation.
The subject should use materials similar to those of the document.
The dictated text should match some parts of the document.
The subject should be asked to sign the text.
Always have a witness.
Repeat with the non-writing hand.
Samples should be both requested and collected.

22. Biometric Signature Pads
Recognizes your signature based on speed, pressure, and rhythm of signing.
Slight differences can be detected.

23. FISH Forensic Information System for Handwriting
Database for handwriting used and maintained by the Secret Service.
Eliminates subjective opinions.
Has been used to verify that no two individuals pen their words exactly the same way.

24. Shortcomings
Standards aren’t always good. Sometimes the standard for comparison is a forgery as well.
Effects of mood, age, drugs, fatigue, and illness on handwriting aren’t always predictable.

25. Linguist
Experts that look at the linguistic content (the way something is written) of a questioned document.
Language that is used can help to establish the writer’s age, gender, ethnicity, level of education, professional training, and ideology.

26. Forgery or Fraud
A forgery is the act of falsifying something with the intent to deceive someone.
Fraud is committed when you profit (some material gain) from a forgery.

27. Check Forgery Checks can be forged by: Ordering someone else’s checks
Directly altering a check
Intercepting someone’s check, altering it, and cashing it.
Creating forged checks from scratch

28. Check forgery Ways to prevent
Checks printed on chemically sensitive paper
Use large font size
High resolution borders that are hard to copy
Print in multiple color patterns
Enhanced fibers that glow under different lights
Use chemical washes that change
colors when a check is altered.

29. Ink
Chromatography--physically separate mixtures of gases, liquids or dissolved solids.
Types
Gas Chromatography
HPLC--high-performance liquid chromatography
TLC--thin-layer chromatography
Paper Chromatography

30. Examples of Chromatography
Liquid Chromatography
Used to identify unknown plant pigments & other compounds.
Paper Chromatography
Can be used to separate the components of inks, dyes, plant compounds (chlorophyll), make-up, and many other substances
Thin-Layer Chromatography
Uses thin plastic or glass trays to identify the composition of pigments, chemicals, and other unknown substances.
Gas Chromatography
Used to determine the chemical composition of unknown substances, such as the different compounds in gasoline shown by each separate peak in the graph below.

31. Paper Chromatography with ink
Two samples of black ink from two different manufacturers run using paper chromatography.

33. Retention Factor
This is a number that represents how far a compound travels in a particular solvent
It is determined by measuring the distance the compound traveled and dividing it by the distance the solvent traveled.

34. Retention Factor

35. Black Marker after Chromatography

36. Gas Chromatograph Separates mixtures
The written record of the results is called a chromatogram.
A typical one will show a series of peaks, with each representing one component of the mixture.
This allows identification of class characteristics.

37. Mass Spectrometer
an instrument that connects to the gas chromatograph.
The substance is exposed to a beam of high- energy electrons.
Fragments then pass through an electronic or magnetic field where they are separated according to their masses.
No two substances produce the same fragmentation pattern, thus producing individual characteristics.

38. paper Weight Color Water marks
Age (binding agents and chemical composition)

39. pencils
Lead
Hardness Scale--a traditional measure of the hardness of the "leads" (actually made of graphite) in pencils. The hardness scale, from softer to harder, takes the form ..., 3B, 2B, B, HB, F, H, 2H, 3H, 4H, ..., with the standard "number 2" pencil being of hardness 2H.

40. Counterfeiting When documents are copied with the intent to deceive.
The most common are traveler’s checks, bonds, and currency.
Counterfeiting on money is investigated by the Secret Service.

41. Counterfeiting Prevention
US currency has specific features to make it difficult to counterfeit.
The number one feature is the special paper it is printed on.
Counterfeit detection markers contain iodine which reacts with fake money to turn blue- black. Claim to be 98% effective.

44. 1. portrait stands out and appears raised
2. there is micro printing on the security threads and portrait.
3. serial number is evenly spaced and same color as treasury seal
4. check letter and quadrant number

45. 5 and 6 Treasury and Federal reserve seals are sharp and crisp.
7. Red and blue fibers throughout and security thread.
8. federal reserve number and letter

46. 9. series
10. check letter and face plate number
11. watermark on right side
12.Colorshift from copper to green.
13. Clear background lines and detail
14. clear distinct border edge

47. Codes and ciphers
Codes--letter combinations or symbols used to represent words or concepts
Interception from terrorists and other war enemies
Ciphers--a message in which letters or symbols replace the actual letters in the message.

49. Code Breaking terms
Encipher (to encode)---to hide the message; top to bottom in a cipher key
Decipher (to decode)---to reveal the message; bottom to top in a cipher key

50. Shift cipher Simplest type of cipher.
Works by shifting the alphabet a certain number of places
There are 25 possible keys.

51. Caesar Shift
Caesar simply replaced each letter in a message with the letter that is three places further down the alphabet.

52. Frequency Analysis
If you have got a message you want to crack, you can use frequency analysis.
In other words, if the sender has tried to disguise a letter by replacing with a different letter, you can still recognize the original letter because the frequency characteristics of the original letter will be passed on to the new letters.
Which letters are the most common in English?

53. Frequency ANalysis

54. Frequency Analysis
These frequencies are averages, and E will not always constitute 12.7 % of all the letters in a text, and may not even be the most common letter.
The longer the message, the more likely it is that will obey the average distribution shown above. However, there are exceptions to this rule.