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Document & Voice Examination

Document & Voice Examination. Objective: 10.0 Describe techniques used to determine the validity of documents. The Unabomber – Ted Kaczynski. Started in 1978 Sent bomb-containing packages to universities (UN) and airliners (A) “UN-A-BOMBer” First fatality was in 1985 (computer store owner)

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Document & Voice Examination

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  1. Document & Voice Examination Objective: 10.0 Describe techniques used to determine the validity of documents.

  2. The Unabomber – Ted Kaczynski • Started in 1978 • Sent bomb-containing packages to universities (UN) and airliners (A) • “UN-A-BOMBer” • First fatality was in 1985 (computer store owner) • Waited 6 more years before sending other packages • 1995 – “Manifesto” to NYT and W. Post

  3. Document Examiners • Examine handwriting and typescript • Requires skills in microscopy, photography, and chromatography • Look for things, such as: • Marks indicating changes to the original document • Indentations from a top sheet • The writing on charred or burned papers • “Gone in 60 Seconds”

  4. Bellringer • SIGN your name 20 times down a column on your paper: Robin Spoon Robin Spoon Robin Spoon Robin Spoon Robin Spoon

  5. Handwriting Analysis • No 2 individuals write exactly alike! • Unconscious variations in: • Angularity • Slope • Speed • Pressure • Letter and word spacing • Relative dimensions of letters • Connections • Pen movement • Writing skill • Finger dexterity

  6. Handwriting Analysis, continued….. • Variations in arrangement of writing on the paper: • Margins • Spacings • Crowding • Insertions • Alignment • Spelling, punctuations, phraseology, and grammar may all be personal.

  7. Challenges to Handwriting Analysis • Insufficient numbers of known writing samples (“exemplars”) available • Not enough words written in the questioned documents • Drugs or alcohol

  8. Collection of Handwriting Exemplars • Ideally, exemplars should be as similar as possible to the questioned document: • Paper (ruled/unruled,type of paper) • Writing implement (tool) • Words • Letter combinations

  9. Collection of Handwriting Exemplars, continued….. • Need an adequate number of exemplars to account for natural variations in writing • Identical signatures are easily identified as forgeries! • Need writing samples from within a 2-3 year period of the questioned document

  10. Collection of Handwriting Exemplars, continued….. • Criminals ASKED to submit handwriting samples will make conscious attempts to alter their handwriting. • How can investigators get around this? • Keep all the other things the same (paper, tool, etc.) • Require many pages of writing • Require the writing of dictation

  11. Hitler’s Diaries • 1981 • 27 volumes + a 3rd volume of Mein Kampf. • 2 experts, American & Swiss, verified the handwriting was identical to the known samples given to them. • The publishing company that won the bid found they were fake. • Whitener – 1954 • Binding threads material – after WWII • Inks

  12. Typescript Comparisons • Fax machines: header (“TTI” = transmitting terminal identifier) • Photocopiers: have transitory defect marks originating from random debris on the glass platen, inner cover, or mechanical portions of a copier

  13. Typescript Comparisons, continued….. • Computer printers - can determine make and model using class characteristics identified under microscope: • Toner application method (impact or non-impact) • Character shapes • Toner differentiation

  14. Typescript Comparisons, continued….. • Typewriters – make and model can be determined using class characteristics: • Typeface size (how many letters per inch) • Type character’s style, shape, and size • Individual typewriters can be identified by variations due to wear and tear

  15. Alterations, Erasures, and Obliterations • Ultraviolet light may reveal areas that have been obliterated with chemicals. • Infrared luminescence: • Blue-green light will cause different inks to glow different colors, showing differences between the original ink and ink used to alter the document. • This may also reveal writing that has been erased or covered by other ink.

  16. Infrared Luminescence on a Washed Store Receipt

  17. Alterations, Erasures, and Obliterations, continued…. • Charred documents: • Infrared photography can sometimes reveal the writing. • They may also try bouncing light off the charred paper at different angles to contrast the writing against the charred background.

  18. Ink Chromatography • Used to identify specific ink used • Breaks down ink into its specific colors • http://www.scienceprojectlab.com/thin-layer-chromatography-for-kids.html

  19. Voice Identification • Name some identifying voice characteristics. • What do you think causes each of these characteristics? • Voices vary based on: • Sizes of vocal cavities • Shape, length, and tension of vocal cords • Voice analysts can graph the sounds of a voice.

  20. Voice Identification, continued….. • Voiceprint: a graph of both the pitch and loudness of a sound vs. time.

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