forensic science questioned documents

Forensic Science Documentation

*
Forensic Science

Questioned Documents

*
A "questioned" document is any signature, handwriting, typewriting, or other mark whose source or authenticity is in dispute or doubtful. Letters, checks, driver licenses, contracts, wills, voter registrations, passports, petitions, threatening letters, suicide notes, and lottery tickets are the most common questioned documents, although marks on doors, walls, windows, or boards would also be included by definition..Who wrote the graffiti on the bathroom wall ?

*
TopicsHandwriting analysisInk Paper Pens and PencilsForgeryCodes and Ciphers

*
Whos Who ?
Forensic DocumentExaminer- involves the analysis and comparison of questioned documents with known material (exemplar) in order to identify the author or origin of the questioned document.
Graphologist- attempts to predict character traits from handwriting examination

*
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??

*
Handwriting analysis
Handwriting analysis involves two phases:

Visual examinationThe hardware ink, paper, pens, pencils, typewriter, printers

*
12 Handwriting Characteristics
Line QualityWord and Letter SpacingLetter ComparisonPen LiftsPen PressureConnecting Strokes
Beginning/Ending StrokesLettering SlantUnusual Letter FormationDiacritic PlacementBaseline HabitsFancy Writing Habits
Visual examination

*
Handwriting Identification
ACEAnalysis of the knowns with a determination of the characteristics found in the knownAnalysis of the questioned or unknown writing and determination of its characteristicsComparison of the questioned writing with the known writing.Evaluation of the evidence, including the similarities and dissimilarities between the questioned and known writing.
Visual examination

*
Collecting Handwriting Samples
The subject should not be shown the questioned documentThe subject is not told how to spell words or use punctuationThe subject should use materials similar to those of the documentThe dictated text should match some parts of the documentThe subject should be asked to sign the textAlways have a witness
Visual examination

*
Collecting Handwriting Samples
Refusal ????*The U.S. Supreme Court decided that handwriting is a part of identifying physical characteristics that arent protected against the 5th*The U.S. Supreme Court decided that providing a handwriting sample doesnt violate the 4th Amendments protections against unreasonable search and seizure.
Visual examination

*
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.
Visual examination

*
Ink
Chromatography--physically separate mixtures of gases, liquids or dissolved.TypesPaper ChromatographyGas ChromatographyHPLC--high-performance liquid chromatographyTLC--thin-layer chromatography

Hardware

*
Paper Chromatographywith Ink
Two samples of black ink from two different manufacturers run using paper chromatography.

Retention Factor (Rf)
This is a number that represents how far a compound travels in a particular solvent

It is determined by measuring the distance the compound traveled and dividing it by the distance the solvent traveled.
Paper Chromatography with Ink

*
Gas chromatography--separates mixtures on the basis of their distribution between a stationary liquid phase and a moving gas phase. The written record of the results is called a chromatogram. A typical one will show a series of peaks, with each representing one component of the mixture. The time required to go from the injection out of the column is known as the retention.
Gas Chromatography with Ink

*
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 of the sample to lose electrons and to acquire a positive charge. These positively charged molecules decompose into numerous fragments. These fragments then pass through an electronic or magnetic field where they are separated according to their masses. The unique feature of mass spectrometry is that no two substances produce the same fragmentation pattern, thus producing individual characteristics.
Mass Spectroscopy with Ink

*
Paper
Combination of wood, cotton and chemical additivesCoatings - improve appearance & surface propertiesFillers - add color strength, and surface textureSizings - make the surface less porous to ink

The types and amounts of each of these additives vary among manufacturers (testable)
Hardware

*
Paper
Water marks-(found in high end papers)-Translucent design created @ manufacture. -Has fewer fibers than rest of paper-Who made it ; when made ; made for whom-Hard to forge
Hardware

*
Pencils
Hardness Scale of Lead--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.
Hardware

*
Pens
Ink Line Striae microscopic lines of non inked areas due to imperfections in the ball or ball housing of the ball point pen
Hardware

*
Forgery
ChecksForgeryCounterfeitAlterationsPaper MoneyCounterfeitIdentitySocial SecurityDrivers license
Credit CardsTheft of card or numberArt--imitation with intent to deceiveMicroscopic examinationElectromagnetic radiationChemical analysis

*
U.S. Counterfeit protection measures
Intaglio Printing Portrait Watermark Color Shifting InkMicro printing Fine Line Engraving Serial Numbers Treasury Seal Security ThreadsUnique PaperEmbedded Red and Blue fibers

*
Intaglio Printing
Intaglio printing is what gives the U.S. currency its distinctive look. This beautiful art is painstakingly produced by engraving on steel plates. Special ink is applied to plates. The plates are first wiped clean, leaving only ink in the grooves, then pressed with enormous pressure. The enormous pressure causes the paper to be embossed with the ink, thus giving the ink a distinctive raised feel that other printing techniques cannot duplicate

*
Portrait
The Treasury maintains that the face is the most recognizable part of money. By moving the portrait to the left, the face will suffer less wear from folding. The move also makes extra room for the watermark on the right side.

*
Watermark
The watermark is created during the paper making process and is caused by variations in the density of the paper. As light passes through these tiny variations in thickness, it creates different tones. When held up to light these varying tones form a clear image

*
Color Shifting Ink
The black to green color-shifting is a new and important element of the redesigned $100 bill. The change in color is the result of multi-layered metallic flakes added to the ink. When the bill is tilted, light reflects off these flakes at different wavelengths and changes colors. This is called color diffraction

*
Micro printing
Appears as just a thin line to the naked eye, but can be easily read upon magnification.

*
Fine Line Engraving
Fine circular lines appear around the portrait of the bill. The clarity and detail of these lines are difficult for scanners and photocopiers to reproduce. These lines often cause a blur during the scanning process.

*
Serial Numbers
No two serial numbers are the same. On the new bills, these serial numbers have been increased to 11 digits.

*
Treasury Seal
The old green Treasury seal hidden behind the "100" has long been part of U.S currency and will remain an important security feature. This detailed combination of green and black is difficult to reproduce

*
Unique Paper
Currency paper has a unique feel and is extremely durable. Is it really 'paper' in the traditional sense? There are no wood fibers or starch in currency paper. Instead, like high quality stationery, currency paper is composed of a special blend of cotton and linen fibers. The strength comes from raw materials continuously refined until the special feel of the currency is achieved. People who handle money on a regular basis, such as bank tellers, can easily determine if a bill is counterfeit by this distinctive feel. The characteristic yellowish-green tint of U.S. currency is another distinctive feature which is, in fact, hard for color photocopiers to accurately match.

*
Security Threads
In the redesigned notes, a security thread will appear in a different location and a different color when held over ultraviolet

*
Red and Blue Fibers
Red and blue fibers have been a longtime ingredient of U.S. currency paper. Special features like these fibers are embedded in currency paper to ensure that reproduction is difficult. While some counterfeiters attempt to draw these fibers onto the surface of the bill, close inspection reveals the absence of the authentic embedded fiber and the clear presence of crude lines drawn on the surface.

*
Codes and Ciphers
Codes--letter combinations or symbols used to represent words or concepts

Ciphers--a message in which letters or symbols replace the actual letters in the message. 1. Simple Substitution CiphersHow many possible sequences are there ?4.0329 x 1026=400,000,000,000,000,000,000,000,000.2. Keyword Number Ciphers3. Telephone Keypad Ciphers4. Masonic Cipher5. Tic-Tac-Toe Cipher

*
Cipher Examples
ABCDEFGHIJKLMNOPQRSTUVWXYZBCDEFGHIJKLMNOPQRSTUVWXYZA

*
Cipher Examples

*
Cipher Examples

CRAZY CRIMINALS
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.

*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*