Post on 27-Dec-2015
Examples of Questioned Documents
• Embezzle by altering books
• Checks• Lottery tickets• Wills • Contracts• Driver’s licenses• Voter registrations• Petitions
• Letters• Autographs• Passports• Hold-up notes• Medical records• Insurance forms• Suicide notes• Diaries
Careers
• Serve a 2 year apprenticeship in a large lab• No college degrees in this specialty• Recommend bachelor’s degree in a lab science• Take courses in law, photography
• Certification by ABFDE =American Board of Forensic Document Examiners
What affects handwriting?
• Illness (stroke or Parkinson’s)
• Fatigue
• Stress
• Impaired vision
• Hand/arm injuries
• Awkward writing position
• Intoxication
1st major case using handwriting analysis
• Kidnapping of Lindbergh baby
• Letters of kidnapper’s signature matched letters from ransom note
Obtain standards
Standard = writing sample = exemplar
• A) Nonrequested standard
• B) Requested standard
Nonrequested standards
• Already exist
• Authentic
• Show true writing habits
• Frequently used words/phrases
• Need to be written at same age as the questioned document
Requested standard
• Made under supervision
• Can use passages from the questioned document
• May be able to fake handwriting for a time
but not for long periods of time.
• Court ordered handwriting samples are legal
• Does not violate 5th amendment (right not to incriminate or testify against oneself)
• Does not violate 4th amendment(sample not considered unreasonable search and
seizure)
Handwriting comparisons
• Look for– Points of similarity– Points of difference
Cursive easier than print to analyze
Handwriting Features
1. Overall form – size, shape, slant, proportion, beginning and ending strokes
2. Line features- writing speed, fluidity, pressure, spacing, connections
Handwriting Features
3. Margins and format –
width of margins
spacing consistency
slant between lines
4. Content
grammar
punctuation
choice of words
Examiner’s conclusions
1. Absolute match
2. Match w/ a high probability
3. Probably match
4. Do not match
5. Inconclusive
FBI handwriting databases
• National Fraudulent Check File
• Bank Robbery Note File
• Anonymous letter file
• FISH = Forensic Information System for Handwriting (scan and digitize documents)
Forgery
• Writing or altering a document w/ the intent to defraud
• Types of forgery:
a. freehand simulation
b. tracing
Clues to detect forgeries
a. Evidence of practice
b. Tremors
c. Uneven writing speed, pressure
d. Pen lifts
e. Patching, retouching
Alterations
• Remove, add, change parts of a document
• Why alter a document?– Financial gain– Create an alibi– Change evidence
Types of alterations
1. Erasures
2. Burning
3. Obliterations (ex.Bleaching)
4. Additions/Overwriting
How to detect erasures
1. Magnifying glass or micropscope
(oblique lighting)
2. UV or infrared light –exposes bits of eraser in the fibers of the paper
3. Lycopodium powder-sticks to rubber particles erasers.
4. Backlighting – turns erased areas light
- darkens correction fluid
Bleaching
• Oxidize/bleaching agents to remove writing
• Ink becomes colorless
• May leave discoloration
• May be visible w/ microscope
Overwriting
• Adds to a document
Ex. Change a 1 to a 9
Ex. Add 0 to a check
Effective if the exact same pen is used
Detecting additions/overwriting
1. Microscopes will show minor diff in - ink colors
- line thickness
- pen pressure
Also: marks on ballpoint pen may be distinctive
2. UV of infrared light exposes diff inks even if they are the same color
- some fluoresce
- some fade
a) Photograph images
b) Chemical analyses of inks
Detecting indentations
a. Oblique lighting
b. Scanning electron microscope
c. ESDA – electrostatic detection apparatus
Paper analysis
Paper is made of:
Cotton
Wood
Chemical additives
brightness, strength, durability, color
Chemical additives
Coatings – improve appearance
Fillers – add color, strength, surface texture
Sizings – make writing appear clear/sharpNote: Chemical additives are unique to each
manufacturer.
Inks
• Is the ink the same for the entire document?
• Was the ink actually in existence at the time?
Analyzing inks
1. Microspectrophotometry measures how inks transmit, absorb, and reflect light
2. TLC= thin layer chromatographyseparates the ink components
Ink Reference Database
• US Secret Service Forensic lab
Note: some manufacturers now add fluorescent-dye tags to their inks (changed annually)
Copiers
• Marks may be left – Mechanism that pulls the paper through the
machine– Scratches in cover glass– Marks on camera lens
Used to determine a. Age of documentb. Which copier was used
Bills
• UV lights -- detect fluorescent strips
• Iodine pens- detect starch (not used in real money)
Websites
• http://www.aafs.org/default.asp?section_id=meetings&page_id=other#JULY%202005
• http://www.freereferral.com/resume/C000558A.php ex. Of cont. ed/ training
• http://www.decinc.ca/comp/compare.html• List of nonrequested samples