Forensic Science Questioned Documents

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Forensic ScienceQuestioned Documents

• Documentation

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Questioned Documents

• Involves the examination of handwriting, ink,
  paper, etc. to ascertain the source or
  authenticity
• Examples include letters, checks, licenses,
  contracts, wills, passports, etc.
• Topics
• Handwriting analysis
• Ink (and pens)
• Paper (and pencils)
• Forgery
• Codes and Ciphers

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COMPARISON

• Forensic Document Examiner--involves the analysis
  and comparison of questioned documents with known
  material in order to identify whenever possible,
  the author or origin of the questioned document.
• Unfortunately, no federal licensing exists. There
  is certification through the ABFDE.

Graphologist--attempts to predict character
traits from handwriting examination
The lower-case "t" in Bundy's signature
"indicates a very low opinion of himself, usually
caused by significant damage to the ego early in
life" -- according to document examiner Brown.
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Handwriting

• Handwriting analysis involves two phases
• The hardware--ink, paper, pens, pencils,
  typewriter, printers
• Visual examination

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Handwriting Characteristics

• Line Quality
• Word and Letter Spacing
• Letter Comparison
• Pen Lifts
• Pen Pressure

• Lettering Slant
• Unusual Letter Formation
• Diacritic Placement
• Baseline Habits
• Body Placement

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Handwriting Identification

• 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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Handwriting Analysis

• Handwriting Sample of President George Bush
• According to Sheila Lowe in her book, Handwriting
  of the Famous and Infamous, President Bushs
  handwriting is fast and highly simplified in
  fairly well-organized writing field.
• Is this a forensic document examiner or a
  graphologist??

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Handwriting Samples

• The subject should not be shown the questioned
  document
• The subject is not told how to spell words or use
  punctuation
• The subject should use materials similar to those
  of the document
• The dictated text should match some parts of the
  document
• The subject should be asked to sign the text
• Always have a witness

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Linguist

• Experts that look at the linguistic content (the
  way something is written) of a questioned
  document.
• Language that is used can help to establish the
  writers age, gender, ethnicity, level of
  education, professional training, and ideology.

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Ink

• Chromatography--physically separate mixtures of
  gases, liquids or dissolved.
• Types
• Gas Chromatography
• HPLC--high-performance liquid chromatography
• TLC--thin-layer chromatography
• Paper Chromatography

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Paper Chromatographywith Ink

• Two samples of black ink from two different
  manufacturers run using paper chromatography.

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Retention Factor (Rf)

• This is a number that represents how far a
  compound travels in a particular solvent
• Rf distance solute travels
• distance of solvent front

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Scientific Equipment

• Gas chromatograph--used to separate mixtures on
  the basis of their distribution between a
  stationary liquid phase and a moving gas phase.
• Chromatogram-the written record of the results is
  called a chromatogram.
• Peaks
• Time tracked on x axis--this is known as
  retention time.
• Example amounts of hot compounds in a
  particular pepper pod.

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Scientific Equipmentcont

• Mass spectrometer--an instrument that connects to
  the gas chromatograph.
• The substance to be identified is exposed to a
  beam of high-energy electrons causing the
  molecules to decompose into numerous fragments.
• These fragments then pass through field where
  they are separated according to their masses.
• No two substances produce the same fragmentation
  pattern, thus producing individual
  characteristics.

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Paper Characteristics

• Weight
• Color
• Water marks
• Age

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Pencils

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

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Forgery

• Credit Cards
• Theft of card or number
• Art--imitation with intent to deceive
• Microscopic examination
• Electromagnetic radiation
• Chemical analysis

• Check Fraud
• Forgery
• Counterfeit
• Alterations
• Paper Money
• Counterfeit
• Identity
• Social Security
• Drivers license

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Codes and Ciphers

• Codes--letter combinations or symbols used to
  represent words or concepts
• Interception from terrorists and other war
  enemies
• Ciphers--a message in which letters or symbols
  replace the actual letters in the message.

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Used as Evidence

• 1. Class characteristic--the type of ink may
  have similar characteristics at the primary
  and/or secondary crime scene, on the suspect or
  on the victim. Handwriting may be used to
  include or exclude a suspect.
• 2. Individual characteristic--With document
  analysis, it is difficult to identify to an
  individual characteristic except with typewriter
  or printer specific marks.

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CRAZY CRIMINALS

• According to Point of View, a magazine published
  by the Alameda county District Attorneys office,
  a guy walked into an Oakland bank and handed the
  teller a note reading, this is a stikkup. Hand
  over all yer money fast.
• Guessing from this that the guy was no rocket
  scientist, the teller replied, Ill hand over
  the cash as long as you sign for it. Its a bank
  policy that all robbers have to sign for their
  money.
• The guy thought this over, then said Uh, I guess
  thats OK. He signed his full name and address.
  Thats where the cops found him a few hours later.

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• You will be given a black ink pen.
• Each of you will write the same message.
• Give the teacher your handwriting sample when you
  are finished.
• Sign your name on the bottom in pencil.

Write the following I have your daughter. Do
what you are told and no one will get hurt. Put
100,000 dollars worth of 20s in a suitcase and
place it in locker number C8160 at the bus depot.
I will get back in touch with you as to the
whereabouts of your daughter. Your loyal fan.