Forensic Science Questioned Documents: Part 1

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

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

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

The Comparison 9/14/2018 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

9/14/2018 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

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.

Document Analysis 9/14/2018 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.

The Hardware - Ink 9/14/2018 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.

9/14/2018 Paper chromatography is a process that separates a mixture into its different components. Paper Chromatography

Paper Chromatography of Ink 9/14/2018 Paper Chromatography of Ink Two samples of black ink from two different manufacturers are separated into their unique components using paper chromatography.

9/14/2018 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.

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

United States International Ink Library 9/14/2018 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.

9/14/2018 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.

9/14/2018 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

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).

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

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

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