1. Document Analysis
Chapter 18

2. Forensic science is a thoughtful and yet not dull, class.
Write this sentence:
Forensic science is a thoughtful and yet not dull, class.

3. Now… write it a second time:
Forensic science is a thoughtful and yet not dull, class.

4. Now… Try to disguise your handwriting by writing the same sentence
Which letters did you change?
Did the slant of the letters change?
Did the size of a particular letter change more than others?

5. Questioned Documents
Questioned documents are any document that has an issue raised or is part of a criminal investigation
Examine handwriting, paper type, ink type
Handwriting gives individual characters
Ink and paper yield class characters

6. Handwriting Analysis
General Style—style taught in particular locations; Palmer method and Zaner- Bloser method are most common in US
During learning, styles look similar, but as mature, styles become individual
Variations—Since handwriting in adults is unconscious, mechanical, physical, and mental functions affect handwriting
Many individual characters in adult handwriting

7. Handwriting Challenges
Need many known samples to make a definitive handwriting match; less effective with fewer standards
Difficulties arise when questioned document has only few words
Difficulties arise when person purposely tries to mask handwriting style in drafting document

8. Handwriting Exemplars
Need many exemplars
Natural variations exist between samples from same person; many exemplars allow for seeing natural variations
For exemplars, writings should be done sitting comfortably, should not know about document, use similar pen and paper to crime scene, dictated sample should contain many same words as questioned document, repeat at least 3 times, and signatures should be taken from other signed documents
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9. Typescript Comparisons
Can be used to determine make and model of photocopier, printer, or fax machine
Takes 10 exemplar samples from each machine to compare to questioned document
Debris on the glass can yield marks that can be matched to a set printer
For faxes, the transmitting terminal indentifier is printed in different type and can be matched more closely
Microscope analysis is done to match printer samples
Typewriters—can determine make and model from sample analysis

10. Document Problems
Erasure—removes words; impressions can be used to recreate lost words
Obliteration—chemically removing words from documents
Infrared luminescence can be used to reform the chemically obliterated items
Crossing-out; often close analysis can recreate words
Charred documents— different angle analysis can make charred areas visible

11. Indented Writings
Marks are made on paper positioned under the paper that was written on
Can be analyzed under oblique or side lighting
Electrostatic polymer and toner powder allows for visualizing indented writings

12. Ink and Paper Comparison
Figure out chemical composition of ink; microspectrophotomer; chromatography
Paper fibers can be analyzed to identify source; paper content, color, texture, thickness, weight, watermarks can all be analyzed
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