1. Glass/Forensic Geology/Document Analysis
Unit 4
Glass/Forensic Geology/Document Analysis

2. Glass

3. Physical Characteristics
Density—mass divided by volume
Refractive index (RI)—the measure of light bending due to a change in velocity when traveling from one medium to another
Fractures
Color
Thickness
Fluorescence
Markings—striations, dimples, etc

4. Chapter 14
Glass as Evidence
Class characteristics; physical and chemical properties
Density/chemical makeup fit all types of similar glass
Individual characteristics
if the fragments can fit together like pieces of a puzzle, the source can be considered unique
Kendall/Hunt

5. Fracture Patterns
Radial fracture lines radiate out from the origin of the impact; they begin on the opposite side of the force
Concentric fracture lines are circular lines around the point of impact; they begin on the same side as the force

6. Sequencing
A high velocity projectile always leaves a hole wider at the exit side of the glass.
Cracks end at intersections with others. This can be used to determine the order that the fractures occurred.

7. Sequencing A Which Came first? B
Notice that the cracks coming off of hole B end when they intersect with cracks from hole A.
This means hole A was made first! B

8. Entrance and Exit Holes
Larger hole on exit side

9. Forensic Geology “Life is hard. Then you die.
Then they throw dirt in your face. Then the worms eat you.
Be grateful it happens in that order.”
—David Gerrold, American science fiction writer

10. Forensic Geology The legal application of earth and soil science
Characterization of earthen materials that have been transferred between objects or locations and the analysis of possible origin or sources

11. Soil
Definition—a mixture of mineral grains, organic matter and any other materials mixed with the sample
Formation
Living matter—plants, animals, microorganisms
Inorganic materials
Climate
Parent materials
Time

12. Soil Comparisons
May establish a relationship or link to the crime, the victim, or the suspect(s)
Physical properties—density, magnetism, particle size, mineralogy
Chemical properties—pH, trace elements
Settling rate

13. Probative Value of Soil
Types of earth material are virtually unlimited. They have a wide distribution and change over short distances.
As a result, the statistical probability of a given sample having properties the same as another is very small
Evidential value of soil can be excellent

14. Soil Evidence
Class characteristics—the type of soil may have similar characteristics at the crime scene, on the suspect or on the victim
Individual characteristics—only if the soil has an unusual or specialized ingredient such as pollen, seeds, vegetation, or fragments.

15. Chapter 15
Document Analysis
Kendall/Hunt

16. Document Analysis
Involves the examination of handwriting, ink and paper to identify the authenticity of documents.
Investigations include:
Verification
Authentication
Characterizing papers, pigments, and inks

17. What Document Analysis is used for
Historical Dating—the verification of age and value of a document or object
Fraud Investigation—focuses on the money trail and criminal intent
Paper and Ink Specialists—date, type, source, and/or catalogue various types of paper, watermarks, ink
Forgery Specialists—analyze altered, obliterated, changed, or doctored documents and photos
Computer Crime Investigators—investigate cybercrime

18. Documents as Evidence
Class characteristics may include general types of pens, pencils or paper.
For instance: Determining the maker of the type of pen or paper
Individual characteristics may include unique, individual handwriting characteristics; trash marks from copiers, or printer serial numbers.
For instance: Most printers print slightly differently which can help identify which printer a document was printed on

19. Document Alterations
Obliterations—removal of writing by physical or chemical means
Can be detected by:
Microscopic examination
UV or infrared (IR) light
Digital image processing

20. Document Alterations
Indentations-marks left by writing on another piece of paper on top of the one in question
Can be detected by:
Angled lighting
Electrostatic detection apparatus (ESDA)

21. Types of Forgery Credit Cards Check Fraud
Counterfeit
Alterations
Paper Money
Identity
Social Security
Driver’s license
Credit Cards
Theft of card or number
Art—imitation with intent to deceive
Microscopic examination
Chemical analysis
Contracts—alterations of contracts, medical records

22. Counterfeiting Dollars are now made of paper with:
In 1996 the government starting adding new security features to our paper money due to the advanced copying technologies that have raised the incidences of counterfeiting.
Dollars are now made of paper with:
Watermarks
faint design made in some paper during manufacture, which is visible when held against the light
Red and Blue threads embedded throughout
Currency forgery is handled by the secret service

23. Paper Analysis Differences to Compare Raw material Weight Density
Thickness
Color
Watermarks
Age
Fluorescence

24. Ink Analysis
Chromatography is a method of physically separating the components of inks
Paper Chromatography of Ink
Ink will travel up the paper differently for different types of ink
Good/Inexpensive way to analyze water based inks
Two samples of black ink from two different manufacturers have been characterized using paper chromatography.

25. Paper Chromatography Lab
We will be testing 5 different markers
Create a hypothesis for each marker BEFORE BEGINNING
We will then compare to an unknown sample
Follow the procedure!!!!!!!
Notice:
Liquid DOES NOT TOUCH THE MARK

26. Handwriting Analysis Handwriting analysis involves two phases:
The tools—ink, paper, pens, pencils, typewriter, printers
To identify the source of the markings/words
Visual examination of the writing

27. Handwriting Characteristics
Word and Letter Spacing
Letter Comparison
Do they make their letters the same way?
Connecting strokes
Do they connect any letters?
Unusual Letter Formation
Are any of their letters odd?
Slant of writing
Backhand = Slanted to the left
Diacritic Placement
Crossing t’s and Dotting i’s

28. Graphology
the study of handwriting as used to infer a person's character.
NOT able to be used in court
NOT Scientific

29. Handwriting Identification
Analysis of the “knowns” with a determination of the characteristics found in the known
Analysis of the questioned or unknown writing and determination of its characteristics
Comparison of the questioned writing with the known writing.
Must have enough exemplars (known characteristics) to compare the unknown sample to

30. Which two match? 1 2 3 4
What features made you say that?

31. Try it out, here is a ransom note, three exemplar (samples) are on the next page, which one matches?

32. Exemplars

33. Match (original on top, exemplar on bottom)

34. Methods of Forgery
Simulated forgery—one made by copying a genuine signature
Traced forgery—one made by tracing a genuine signature
Blind forgery—made without a model of the signature

35. How to disguise your handwriting
Change from printing to cursive
Or vice versa
Write with your other hand