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Computer AnalysisComputer Analysis

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15. Linguist15. Linguist

Experts that look at the linguistic Experts that look at the linguistic content (the way something is content (the way something is written) of a questioned document.written) of a questioned document.

Language that is used can help to Language that is used can help to establish the writer’s age, gender, establish the writer’s age, gender, ethnicity, level of education, ethnicity, level of education, professional training, and ideology.professional training, and ideology.

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There are several mechanical devices and machines a document examiner encounters

Computers TypewritersTypewriter ribbonPhotocopiersPrintersFax machines

20. Typescript 20. Typescript ComparisonsComparisons

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16. & 17. Document 16. & 17. Document AlterationsAlterations

ObliterationsObliterations——removal of writing by removal of writing by physical or chemical means can be physical or chemical means can be detected by:detected by: Microscopic examinationMicroscopic examination UV or infrared (IR) light UV or infrared (IR) light Digital image processingDigital image processing

Indentations can be detected by:Indentations can be detected by: Oblique lightingOblique lighting Electrostatic detection apparatus (ESDA)Electrostatic detection apparatus (ESDA)

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Alterations, Erasures, and Alterations, Erasures, and ObliterationsObliterations

The most common way to alter a document is erasure, either using an Indian rubber erasure, or with chemicals.

These changes can be seen under a microscope using direct or side lighting.

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19. Alterations, Erasures, and 19. Alterations, Erasures, and ObliterationsObliterations

Examiners often use Infrared Luminescence.When some inks are exposed to blue-green light, they absorb the radiation and reradiate infrared light, making any alterations visible with infrared sensitivefilm.

Infrared luminescencecan also reveal writing that has been erased.

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Infrared Luminescence Infrared Luminescence examplesexamples

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Alterations, Erasures, and Alterations, Erasures, and ObliterationsObliterations

16. Obliteration is the act of blotting or smearing over a writing or printing to make the original unreadable.

The contents of a charred document can sometimesBe revealed through infrared photography.

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17. Other Document 17. Other Document EvidenceEvidence

Indented writings are the impressions left on papers positioned under a piece of paper that has been written on.

Sometimes the document is readable

with oblique lighting, or angling thedocument againstthe light.

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18. Other Document Problems18. Other Document Problems

Electrostatic charge can beapplied to the surface if theindented document, thenlayered with toner powder to produce an image.

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9. Ink9. Ink

Chromatography--physically separates Chromatography--physically separates mixtures of gases, liquids or mixtures of gases, liquids or dissolved solids.dissolved solids.

TypesTypes Gas ChromatographyGas Chromatography HPLC--high-performance liquid HPLC--high-performance liquid

chromatographychromatography TLC--thin-layer chromatographyTLC--thin-layer chromatography Paper ChromatographyPaper Chromatography

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Retention Factor (RRetention Factor (Rff))

This is a number that This is a number that represents how far a represents how far a compound travels in compound travels in a particular solventa particular solvent

It is determined by It is determined by measuring the measuring the distance the distance the compound traveled compound traveled and dividing it by the and dividing it by the distance the solvent distance the solvent traveled.traveled.

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Specialized LigthingSpecialized Ligthing

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PaperPaper

The paper on which thedocument is written orprinted on is alsoanalyzed by the examiner.

Handwriting sample of George W. Bush

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13. & 14. Paper13. & 14. Paper

DifferencesDifferences Raw materialRaw material WeightWeight DensityDensity ThicknessThickness ColorColor WatermarksWatermarks AgeAge FluorescenceFluorescence

True Watermark

Forged Watermark

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13. Other Document Problems13. Other Document ProblemsPaper examined under a microscope can reveal:

Fibers Fillers

Pigments Additives

Non-coated Coated

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PencilsPencils

LeadLead Hardness ScaleHardness Scale——a traditional a traditional

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

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Codes and CiphersCodes and Ciphers Codes--letter combinations or Codes--letter combinations or

symbols used to represent symbols used to represent words or conceptswords or concepts Interception from terrorists Interception from terrorists

and other war enemiesand other war enemies Ciphers--a message in which Ciphers--a message in which

letters or symbols replace the letters or symbols replace the actual letters in the message.actual letters in the message.

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EvidenceEvidence Class characteristics may include Class characteristics may include

general types of pens, pencils or general types of pens, pencils or paper.paper.

Individual characteristics may Individual characteristics may include unique, individual include unique, individual handwriting characteristics; trash handwriting characteristics; trash marks from copiers, or printer marks from copiers, or printer serial numbersserial numbers..

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Handwriting Handwriting IdentificationIdentification

“ACE” Analysis of the “knowns” with a determination

of the characteristics found in the known 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.

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CRAZY CRIMINALSCRAZY CRIMINALSAccording to Point of View, a magazine According to Point of View, a magazine

published by the Alameda county District published by the Alameda county District Attorney’s office, a guy walked into an Attorney’s office, a guy walked into an Oakland bank and handed the teller a Oakland bank and handed the teller a note reading, note reading, “this is a stikkup. Hand “this is a stikkup. Hand over all yer money fast.”over all yer money fast.”

Guessing from this that the guy was no Guessing from this that the guy was no rocket scientist, the teller replied, “I’ll rocket scientist, the teller replied, “I’ll hand over the cash as long as you sign hand over the cash as long as you sign for it. It’s a bank policy that all robbers for it. It’s a bank policy that all robbers have to sign for their money.”have to sign for their money.”

The guy thought this over, then said “Uh, I The guy thought this over, then said “Uh, I guess that’s OK.” He signed his full name guess that’s OK.” He signed his full name and address. That’s where the cops and address. That’s where the cops found him a few hours later.found him a few hours later.

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More aboutMore aboutDocument AnalysisDocument Analysis

For additional information about For additional information about document and handwriting analysis, document and handwriting analysis, check out Court TV’s Crime Library at:check out Court TV’s Crime Library at:

lwww.crimelibrary.com/criminal_mind/forensics/literary/1.htmlwww.crimelibrary.com/criminal_mind/forensics/literary/1.htm

Or forgery cases at:Or forgery cases at:www.crimelibrary.com/criminal_mind/scams/lincoln_forgers/index.htmlwww.crimelibrary.com/criminal_mind/scams/lincoln_forgers/index.html