Questioned Documents

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Questioned Documents
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Summary

• Document Analysis
• Ink Examination
• Paper Examination
• Machine Examination (typewriter, printer)

Handwriting Analysis
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Questioned Documents

• What pen wrote this?
• What type of paper is it written on?
• Has it been altered?

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Questioned Documents

• Ink Analysis

• Reveal a document was written with a specific
  writing instrument.

• Reveal alterations words added/removed from a
  document

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Questioned Documents gt Ink Analysis

• Ink Analysis (matching pens, etc.)

• An ink will have specific chemical components.

• The same ink can be used in many pens. (even
  different brands)

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Questioned Documents gt Ink Analysis

• Ink Analysis (matching pens, etc.)

• Look at under alternative light (different
  wavelengths)

• UV and Infrared light

• Glow, Transparent, Nothing

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Questioned Documents gt Ink Analysis

• Ink Analysis (matching pens, etc.)

• Look at under alternative light (different
  wavelengths)

• UV and Infrared light

• Glow, Transparent, Nothing

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Questioned Documents gt Ink Analysis

• Ink Analysis (matching pens, etc.)

• Look at under alternative light (different
  wavelengths)

• UV and Infrared light

• Glow, Transparent, Nothing

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Questioned Documents gt Ink Analysis
Thin Layer Chromatography (TLC)

• Place punch of ink in solvent

• Drop on paper (stationary phase)

• Put in liquid (mobile phase)

• Liquid travels up paper separates components of
  ink

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Questioned Documents
Thin Layer Chromatography (TLC)
Stationary Phase
Paper
Separated Ink
Start Dot
Mobile Phase
Solvent
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Questioned Documents gt Ink Analysis

• Ink Analysis (alterations)

Alternative lighting may indicate alterations
with different ink.
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Questioned Documents gt Ink Analysis

• Ink Analysis (alterations)

Alternative lighting may indicate alterations
with different ink.
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Questioned Documents gt Paper Analysis

• Paper Analysis

• Pages may have been added to a document.
• Question of where/when the document originated.

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Questioned Documents gt Paper Analysis

• Class characteristics compared

• Location/number of staple holes.

• Different types of paper receive different
  additives during manufacturing.

• Paper size and thickness

• Opacity, Color, Brightness (additives affect)

• Watermarks

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Questioned Documents

• Machine Analysis

• Typewriters/printers can leave individual markings

• Can be class characteristics or individual
  characteristics

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Handwriting Analysis

• Who wrote this?

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Handwriting Analysis

• When is handwriting important?

• Threatening letters
• Forged signatures
• Forged prescriptions/other documents

Is handwriting specific to an individual?
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Handwriting Analysis
Is handwriting specific to an individual?

• Handwriting is different among individuals.

• Handwriting does not change over time.

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Handwriting Analysis
When is handwriting style set?

• Coordination and visual perception affect
  development.

• Handwriting style usually set by late teenage
  years.

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Handwriting Analysis
Collection of Handwriting Evidence
Unknown (questioned) sample compared to known
samples.
How are known samples collected?
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Handwriting Analysis
Two types of known samples
Requested Samples

• Good can mimic conditions (pen/paper/position)
• Bad suspect can disguise writing.

Non-requested Samples (records, applications)

• Good reveals normal writing habits
• Bad need large sample authenticated for court

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Handwriting Analysis
What does the examiner look for?

• Slant
• Spacing
• Height ratio

• Beginning and ending strokes
• Size

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Handwriting Analysis

• Who wrote this?