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Documentation Analysis

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Presentation on theme: "Documentation Analysis"— Presentation transcript:

1 Documentation Analysis
Day 6

2 Do Now What are the two types of handwriting samples investigators can examine?

3 Flashcard Check Any means of communication that is suspect, entirely or in part, as to authenticity or origin. Questioned Document The object or material that has received handwriting or mechanical printing. Writing Surface The material the records markings on a receiving surface. Transfer Medium

4 Flashcard Check To prove that something is true, real, or what it is said to be. Authenticate A change in the physical appearance or meaning of something, often only slightly. Alteration To make an illegal copy of something in order to deceive. Forgery

5 Documentation Analysis
New Flashcard Vocab 13) Requested Writings: Writing Samples obtained from an individual either voluntarily or as the result of a court order. 14) Collected Writings: Writing samples obtained from a variety of sources that represent a valid sample of an individual's writing. 15) Normal Variation: That variation in writing characteristics seen by examination of numerous examples of an individual's writing.

6 Documentation Analysis
Erasures One way a document may be altered is by erasing something that was already printed on it, perhaps to replace it with something else. Another word for erasure is: 16) Obliteration: To wipe out, rub off, or erase with a chemical.

7 Documentation Analysis
Some erasures are made by physically rubbing the top layer of the paper off, such as pencil erasing. Some erasures are made by using a chemical that bleaches out the print. 17) Ink Eradicator: A fluid used to decolorize ink on a document to make it invisible.

8 Documentation Analysis
Tools for Investigating Documents When a physical erasure is made, some of the paper is rubbed of, disturbing the fibers and leaving the paper slightly thinner in that area. It may not be visible to the naked eye, but investigators can see the difference using different methods.

9 Documentation Analysis
One method investigators use is to dust the paper with a powder. The powder will become trapped under the rougher disturbed fibers. Examiners can also use iodine fuming to see where fibers have been disturbed. Iodine fumes turn the paper brown where erasures have occurred.

10 Documentation Analysis
Another method involves the use of a 18) Light Box: A box with a very even light source behind a piece of ground or translucent glass or plastic, which is used to backlight an object.

11 Documentation Analysis
Different inks are made up of different dyes, pigments, and solvents. Some combinations may look the same to the naked eye, but differences can be detected under ultraviolet or infrared light.

12 Documentation Analysis
Investigators have a tool for looking at documents under these different light sources called a 19) Spectral Comparator: An instrument that has a number of light sources, filters, and a video camera that greatly increases what one can see on a document compared to what our naked eyes can normally observe.

13 Documentation Analysis
Flashcard Check The impressions left behind on a writing surface, or the surface underneath, by the writing instrument. Indentations Activity: Make an indentation on one of your index cards - you may have to press hard. Trade with a neighbor and see if you can read what they wrote - try rubbing lightly over it with your pencil.

14 Documentation Analysis
Indentations can be revealed by rubbings, but investigators prefer to use 20) Oblique lighting: Using a bright light at a very low angle to a document to make indentations on the sheet more visible by shadowing them.

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An even better tool that investigators have for viewing indentations is called a 21) Electrostatic Detection Apparatus (ESDA): An instrument developed specifically for making indented writing visible on a clear cover sheet without altering the original document.

16 Documentation Analysis
Examiners can also use more sophisticated chromatography techniques 22) Thin-Layer Chromatography (TLC): A separation technique using a plate with a thin layer of an absorbent and capillary action to move a solvent up the plate.

17 Documentation Analysis
23) High-Performance Liquid Chromatography (HPLC): A separation technique using high pressure to force a solvent through a tube packed with an absorbent.

18 Documentation Analysis
Exit Card


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