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Questioned Documents

Questioned Documents

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Questioned Documents

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  1. Questioned Documents

  2. Summary Document Analysis • Ink Examination • Paper Examination • Machine Examination (typewriter, printer) Handwriting Analysis

  3. Questioned Documents What pen wrote this? What type of paper is it written on? Has it been altered?

  4. Questioned Documents Ink Analysis • Reveal a document was written with a specific writing instrument. • Reveal alterations: words added/removed from a document

  5. Questioned Documents > 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)

  6. Questioned Documents > Ink Analysis Ink Analysis (matching pens, etc.) • Look at under alternative light (different wavelengths) • UV and Infrared light • Glow, Transparent, Nothing

  7. Questioned Documents > Ink Analysis Ink Analysis (matching pens, etc.) • Look at under alternative light (different wavelengths) • UV and Infrared light • Glow, Transparent, Nothing

  8. Questioned Documents > Ink Analysis Ink Analysis (matching pens, etc.) • Look at under alternative light (different wavelengths) • UV and Infrared light • Glow, Transparent, Nothing

  9. Questioned Documents > 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

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

  11. Questioned Documents > Ink Analysis Ink Analysis (alterations) Alternative lighting may indicate alterations with different ink.

  12. Questioned Documents > Ink Analysis Ink Analysis (alterations) Alternative lighting may indicate alterations with different ink.

  13. Questioned Documents > Paper Analysis Paper Analysis • Pages may have been added to a document. • Question of where/when the document originated.

  14. Questioned Documents > 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

  15. Questioned Documents Machine Analysis • Typewriters/printers can leave individual markings • Can be class characteristics or individual characteristics

  16. Handwriting Analysis Who wrote this?

  17. Handwriting Analysis When is handwriting important? • Threatening letters • Forged signatures • Forged prescriptions/other documents Is handwriting specific to an individual?

  18. Handwriting Analysis Is handwriting specific to an individual? • Handwriting is different among individuals. • Handwriting does not change over time.

  19. Handwriting Analysis When is handwriting style set? • Coordination and visual perception affect development. • Handwriting style usually set by late teenage years.

  20. Handwriting Analysis Collection of Handwriting Evidence Unknown (questioned) sample compared to known samples. How are known samples collected?

  21. 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

  22. Handwriting Analysis What does the examiner look for? • Slant • Spacing • Height ratio • Beginning and ending strokes • Size

  23. Handwriting Analysis Who wrote this?