1. Forensic Science Questioned Documents: Part 1

2. Questioned Documents
Any object that contains handwritten or typewritten/printed markings whose source or authenticity is in doubt is considered a question document.

3. Questioned Documents These include: Letters Checks Driver’s license
Contracts
Wills
Passports
Lottery tickets

4. Questioned Documents
Questioned documents may also include writings or markings found on walls, windows, doors, etc.

5. The Comparison
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A questioned document will be compared to a known exemplar or sample (if available).
Historical Example – The Bixby Letter
The letter was the inspiration for the movie Saving Private Ryan
However, many believe that Lincoln did not write the letter

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The Bixby Letter was compared to the known writings of both Abraham Lincoln and John Hay who was one of the White House secretaries. Which was the questioned document? What was the exemplar?
The Comparison

7. Questioned Documents
The document examiner must determine the authenticity or source of a document through handwriting examination and the use of microscopy, photography, chromatography to note any change or alterations.
The examiner must be able to recognize erasures and overwriting in attempt to change the original meaning of a document.
The examiner must be able to reconstruct charred or burned paper.

8. Document Analysis
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Document analysis involves two phases:
1. A determination of the hardware used to make the text. Ink, paper, pencils, typewriters, photocopiers, printers and fax machines are types of hardware.
2. Visual examination of the handwriting
characteristics on the document.

9. The Hardware - Ink
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Ink is a liquid that is composed of pigments, dyes and other materials.
An examiner will analyze the ink of the known and questioned document to determine if the two documents were made by the same pen.
The analysis of ink involves chromatography.
This process physically separates the different components of the ink.

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Paper chromatography is a process that separates a mixture into its different components.
Paper Chromatography

11. Paper Chromatography of Ink
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Paper Chromatography of Ink
Two samples of black ink from two different manufacturers are separated into their unique components 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.
It is determined by measuring the distance the solute traveled and dividing it by the distance the solvent traveled.

13. You are analyzing a ransom note
You are analyzing a ransom note. It is your job to determine if any of the 6 pens found in the suspect’s home office could have been used to write the note. Write a procedure for the steps you will use to analyze the number of pigment colors found in each of the inks and the Rf value of each pigment within the ink.
Chromotography Lab

14. United States International Ink Library
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United States International Ink Library
The Secret Service and the Internal Revenue Service partnered to create and maintain this database.
Over 8,500 inks dating back to the 1920’s are included in the collection.
Each year new pen and ink formulas are added to the database.

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The Hardware - Paper
Most paper is made from wood pulp. Some types of paper are treated with chemicals or include cotton fibers.
For example, newspaper contains only wood pulp, but shopping bags are treated with sulfate for extra strength.

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The Hardware - Paper
The paper used for both the questioned document as well as the exemplar will be evaluated using:
Weight – assigned based on the weight of a ream
Thickness – measured to 1/1000th of an inch
Color – fillers are added for certain colors
Water marks – a translucent design viewed by holding the paper to the light
Age – determined by Carbon-14 dating

17. The Hardware - Pencils
Most pencils are wooden cylinders with a graphite core.
The core is measured by the Hardness Scale.
The Hardness Scale is a traditional measure of the hardness of the "leads" (actually made of graphite) in pencils.
The hardness scale has a range from 9B (the softest) to 9H (the hardest).

18. The Hardness Scale H stands for hard B for black F for fine .
The typical #2 pencil used in school is a HB pencil.
The Hardness Scale

19. The Hardware - Typewriter
Although typewriters are not as widely used today, there are still typescripts that need to be analyzed.
An examiner will need to determine:
1. The make and model of the typewriter.
2. Any unique feature that will link the questioned document to a particular typewriter.
The Hardware - Typewriter

20. The Hardware – Photocopiers, Printers and Fax Machines
The onset of digital technology created many new machines capable of creating documents.
Document examiners are now asked to examine copied documents from photocopiers, printers and fax machines.
Examiners will be asked to determine
The make and model of these machines.
Any markings or smudges on the copied document that are unique to the machine.
The Hardware – Photocopiers, Printers and Fax Machines