1. Fingerprints
Chapter 14

2. History of Fingerprinting
Scientist
Date
(approximate)
Contribution to Forensics
Alphonse Bertillon
Henry Fauld
Francis Galton
Dr. Juan Vucetich
Sir Richard Edward Henry

3. History of Fingerprinting
Alphonse Bertillon
1883 – First systematic attempt at personal identification
Used portrait parlé - verbal description of perpetrator’s physical characteristics and dress provided by an eyewitness
And used anthropometry – a system of precise body measurements
System used for over two decades

4. History of Fingerprinting
Henry Fauld
1880 – Scottish physician published articles suggesting that skin ridge patterns could be important in identification of criminals
Explained how fingerprints were used to solve a crime
Offered to help set up system at Scotland Yard; offered rejected

5. History of Fingerprinting
Francis Galton
1892 – Published the textbook Fingerprints
Discussed anatomy of fingerprint and methods of recording
Introduced the three patterns – loop, whorl, and arch
Demonstrated that no two prints were identical and that prints do not change over a lifetime
British government adopted fingerprinting as a supplement to the Bertillon system

6. History of Fingerprinting
Dr. Juan Vucetich
1891 – Argentinian police officer
Devised a classification system for prints so that they can be filed and searched easily
Although revised, it is still used in many Spanish speaking countries

7. History of Fingerprinting
Sir Edward Richard Henry
1897
Proposed another type of classification system adopted by Scotland Yards
Most English speaking countries use a modified version

8. History of Fingerprinting
Will West
1903
Proved Bertillon’s system inaccurate
Convict arrived at prison to find another William West with the same body measurements and similar physical characteristics
Fingerprints were use to distinguish prisoners

9. History of Fingerprints
New York City Civil Service Commission
1901
First systematic and official use of fingerprints for personal identification
Used to certify all civil service applications

10. Fundamental Principles of Fingerprints
A Fingerprint is an Individual Characteristic; No Two Fingerprints Have Yet Been Found to Possess Identical Ridge Characteristics.
Galton calculated the possible existence of 64 billion different fingerprints!
Ridge Characteristics, also known as minutiae, are ridge endings, enclosures, and other ridge details that must match in two fingerprints in order for their common origin to be established
In judicial proceedings, a point-by-point comparison must be demonstrated
There are as many as 150 ridge characteristics on the average fingerprint

11. Fundamental Principles of Fingerprints
A Fingerprint Will Remain Unchanged During an Individual’s Lifetime
The pattern of ridges determined by the dermal papillae, the boundary between the first two layers of skin
Pores are present on the top layer releasing sweat and oil – this can be transferred to a surface when touched leaving an invisible impression – latent fingerprints

12. Fundamental Principles of Fingerprints
Fingerprints Have General Ridge Patterns that Permit Them to be Systematically Classified.
All fingerprints are divided into three classes on the basis of their general pattern: loops, whorls, and arches
Refer to Fingerprinting 101 to identify the various classes of fingerprints.

13. Ridge Characteristics
The individuality of a fingerprint is not determined by its general shape but by careful study of its ridge characteristics or its minutiae
No two fingers have yet been found to possess identical ridge characteristics

14. Basic and composite ridge characteristics (minutiae)
Example
ridge ending
         
bridge
bifurcation
double bifurcation
dot
trifurcation
island (short ridge)
opposed bifurcations
lake (enclosure)
ridge crossing
hook (spur)
opposed bifurcation/ridge ending

15. Ridge Characteristics
Ridge Dots
Bifurcations
Trifurcations
Ending Ridge
Ridge Crossing
Enclosures (Lakes)
Short Ridges (Islands)
Spurs (Hooks)
Bridges

16. Ridge Dots
An isolated ridge unit whose length approximates its width in size             
                

17. Double Bifurcation Opposed Bifurcation
Bifurcations
The point at which one friction ridge divides into two friction ridges
           
Double Bifurcation     Opposed Bifurcation

18. Trifurcations
The point at which one friction ridge divides into three friction ridges 

19. Ending Ridge
A single friction ridge that terminates within the friction ridge structure
         

20. Ridge Crossing
   A point where two ridge units intersect       

21. Enclosures (Lakes)
A single friction ridge that bifurcates and rejoins after a short course and continues as a single friction ridge

22. Short Ridges (Islands)
Friction ridges of varying lengths
         

23. Spurs (Hooks)
A bifurcation with one short ridge branching off a longer ridge

24. Bridges
A connecting friction ridge between parallel running ridges, generally right angles

25. Classification of Fingerprints
System used by FBI converts ridge patterns on all 10 fingers into numbers in the form of a fraction
Fingerprint cards can be classified into 1024 groups
The presence or absence of a whorl pattern is the basis for the determination of the primary classification

26. Classification Fingers are paired in the following sequence:
R. Index R. Ring L. Thumb L. Middle L. Little
R. Thumb R. Middle R. Little L. Index L. Ring
If a whorl pattern is found on any finger in the first pair, it is assigned a value of 16; on the second pair, a value of 8; on the third pair, a value of 4; on the fourth pair, a value of 2; and on the fifth pair, a value of 1. Any finger have an arch or loop is assigned a value of 0.
Add all the values for the 10 fingers and then add 1 to both the numerator and denominator.
The fraction obtained is the classification.
For example: =

27. Automated Fingerprint Identification System
The AFIS (Automated Fingerprint Identification System) uses automatic scanning devices that convert the image of a fingerprint into digital minutiae that contain data showing ridges at their points of termination and the branching of ridges into two ridges (bifurcations).
AFIS has brought about a fundamental change to the way criminal investigators operate, allowing them to spend less time developing suspect lists and more time investigating the suspects generated by the computer.

28. Types of Prints
Visible Prints are made when the fingers touch a surface after the ridges have been in contact with a colored material such as blood, paint, grease or ink.
Plastic prints are ridge impressions left on a soft material such as putty, wax, soap or dust.
Latent Prints are impressions caused by the transfer of body perspiration or oils present on finger ridges to the surface of an object.

29. Locating Latent Prints
Locating latent prints requires the use of techniques that will make the prints visible.
Latent prints on hard and nonabsorbent surfaces (e.g., glass, mirror, tile and painted surfaces require the use of powders and/or Super Glue to make the prints visible.
Prints on soft or porous material (e.g., paper, cardboard, cloth) generally require treatment with one or more chemicals to make them visible.

30. Methods of Detecting Fingerprints
Each group will be assigned one of the methods used for detecting fingerprints.
Read about the method in your book on pages and answer the following questions in your notes:
What type of print does it detect?
On which type of surface does it work best?
What is the process used to visualize the prints and retrieve them?
Type up your notes in a few concise lines on word document to present to the class.

31. RUVIS
Sometimes the most difficult aspect of fingerprint examination can be the location of the print.
Recent advances in fingerprint technology have led to the development of an ultraviolet image converter for the purpose of detecting latent prints.
This device, called the Reflected Ultraviolet Imaging System (RUVIS), can locate prints on most nonabsorbent surfaces without the aid of chemical or powder treatments.
RUVIS detects the print in its natural state by aiming UV light at the surface suspected of containing prints. When the UV light strikes the fingerprint, the light is reflected back to the to the viewer, differentiating the print from its background surface.
The transmitted UV light is then converted into visible light by an image intensifier. Once located in this manner, the crime-scene investigator can develop the print in the most appropriate manner.

32. Other techniques for detecting prints
Iodine Fuming is a technique for visualizing latent fingerprints by exposing them to iodine vapors.
Sublimation is a physical change from the solid directly to the gas state.
Ninhydrin is a chemical reagent used to develop latent fingerprints on porous material by reacting with amino acids in perspiration.

33. Other techniques for detecting prints
Physical developer: a silver-based reagent formulated to develop latent fingerprints on porous surfaces.
Super Glue Fuming: A technique used for visualizing latent fingerprints on non-porous surfaces by exposing them to cyanoacrylate vapors; named for the commercial product “Super Glue”.

34. Preservation of Developed Prints
Once the print has been visualized, it must be permanently preserved.
1. Photographs are taken
Provide an overall view of print
Provide view in respect to other evidence
2. Prints are preserved
Small items easily transported
have prints covered with cellophane
to protect it
Larger items can have the print
“lifted”

37. Digital Imaging
Digital Imaging is the process by which a picture is converted into a digital file.
When fingerprints are lifted from a crime scene, they are often not in perfect condition. This makes their analysis very difficult.
With the help of digital imaging software, fingerprints can now be enhanced for the most accurate and comprehensive analysis.