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Monday, 12/1 Homework: Bring 1 to 2 aluminum cans for Thursday Agenda for today: Lecture on history of fingerprints, types of prints, and visualization.

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Presentation on theme: "Monday, 12/1 Homework: Bring 1 to 2 aluminum cans for Thursday Agenda for today: Lecture on history of fingerprints, types of prints, and visualization."— Presentation transcript:

1 Monday, 12/1 Homework: Bring 1 to 2 aluminum cans for Thursday Agenda for today: Lecture on history of fingerprints, types of prints, and visualization of prints.

2 History of Personal Identification O The Bertillon System was the 1 st attempt at a personal identification system O Introduced by French police expert Alhonse Bertillon in 1883 O Relied on a detailed description (portrait parle) of the subject, combined with full length and profile photographs and system of precise body measurement (anthropometry)

3 Anthropometry O Rested on the premise that the dimensions of the human bone system remained fixed from the age of 20 until death O It was thought that no 2 skeletons could have the same measurements O 11 measurements of the human anatomy was recommended O Height, reach, width of head, length of left foot

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5 A Bertillon "booking" Card

6 Bertillon Fingerprint Card

7 Henry Fauld O Scottish Physician O 1 st person to realize the potential application of fingerprinting to personal identification O Recognized the importance of fingerprints as a means of identification, but devised a method of classification as well. O He discussed fingerprints as a means of personal identification, and the use of printers ink as a method for obtaining such fingerprints. O he is also credited with the first fingerprint identification of a greasy fingerprint left on an alcohol bottle.

8 Henry Fauld

9 Sir Francis Galton O British anthropologist (and a cousin of Charles Darwin) O Began his observations of fingerprints as a means of identification in the 1880's O Published Fingerprints in 1892 O Calculated that the odds of two individual fingerprints being the same were 1 in 64 billion. O Identified the characteristics (minutia) by which fingerprints can be identified and are known as “Galton's Details”.

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11 Juan Vucetich O Argentine Police Official O 1891: began the first fingerprint files based on Galton pattern types – still used in some S. Am countries today O 1892: made the first criminal fingerprint identification. O Identified a woman by the name of Rojas, who had murdered her two sons, and cut her own throat in an attempt to place blame on another. O Her bloody print was left on a door post, proving her identity as the murderer.

12 Juan Vucetich

13 Sir Edward Richard Henry O Developed another classification system for fingerprints in 1901 O Scotland Yard adopted the Henry system in 1901 O In its original configuration, the Henry system could only accommodate up to 100,000 samples. As more and more prints were collected over time, additional extensions were added. O The United States uses a modified version of the Henry system

14 What happened to Bertillon in 1903? O In 1903, a prisoner by the name Will West was sentenced to incarceration at the United States Penitentiary at Leavenworth, Kansas. O During his in processing, the records clerk obtained Will West's Bertillon measurements and photograph. O Will West denied ever being incarcerated at the facility.

15 O Will West's Bertillon Measurements 178.5; 187.0; 91.2; 19.7; 15.8; 14.8; 6.6; 28.2; 12.3; 9.7

16 O The records clerk, having referenced his Bertillon measurements into the system, retrieved the Bertillon card for a William West. O Will West denied that the William West card was his. O Subsequent investigation disclosed that William West had previously been incarcerated in the facility until September 9, 1901.

17 O William West's Bertillon Measurements 177.5; 188.0; 91.3; 19.8; 15.9; 14.8; 6.5; 27.5; 12.2; 9.6; 50.3

18 William West Will West Will West's Bertillon Measurements 178.5; 187.0; 91.2; 19.7; 15.8; 14.8; 6.6; 28.2; 12.3; 9.7 William West's Bertillon Measurements 177.5; 188.0; 91.3; 19.8; 15.9; 14.8; 6.5; 27.5; 12.2; 9.6

19 O By examining the photographs, one can see the failure of the Bertillon system. O Compare the Bertillon measurements in particular, keeping in mind the various factors that would affect the measurements. O This failure strengthened the science of fingerprints as the normally accepted method of personal identification. O The authorities compared their fingerprints and determined that Will West was not the previously recorded William West

20 Methods Of Detecting Fingerprints Objectives: 1. Distinguish visible, plastic, and latent fingerprints. 2. List the techniques for developing latent fingerprints on porous and nonporous objects. 3. Describe the proper procedures for preserving a developed latent fingerprint.

21 Distinguish visible, plastic, and latent fingerprints. O Visible prints: Made when the finger deposits a visible material such as ink, dirt, or blood onto a surface O Plastic prints: Fingerprints impressed into a soft surface O Latent (invisible) prints: Caused by the transfer of body perspiration or oils present on finger ridges to the surface of an object

22 Locating Fingerprints O The method of visualization is determined by the type of surface being examined: O Hard/nonporous surfaces: Powders and Super Glue fuming O Soft/porous surfaces: Chemical treatment O RUVIS (Reflected Ultraviolet Imaging System) O Aims UV light onto a non-absorbent surface to help locate fingerprints O Prints are then developed in the appropriate manner

23 List the techniques for developing latent fingerprints on porous and non-porous surfaces. O Powders (grey/black, metallic, fluorescent) O Chemical methods: O Iodine fuming O Ninhydrin O Physical developer O Super Glue fuming O DFO O Fluorescence

24 Powders O Used mostly on dry, nonporous surfaces O Applied with camel’s hair or fiberglass brush O Powders adhere to the perspiration and oil residues left by the ridges O Grey/black: O Most common O Used on lighter surfaces O Magnetic: O Less damaging to print O Good for leather and rough plastics O Fluorescent: O Used in conjunction with UV light O Prevents prints from being obscured by color of the surface

25 Iodine Fuming O Oldest of the chemical methods O Process: O Iodine crystals and suspect material placed in a cabinet and heated O Iodine goes directly from solid crystals to a gas (sublimation) when heated O Vapors combine w/ the print to make it visible O It is thought that the iodine combines with fatty oils or residual water in the fingerprint, but not known for sure O Prints that are developed using iodine fuming are not permanent O Can be extended by a month to a year with the application of a 1% solution of starch in water

26 Ninhydrin O Process: O Sprayed onto porous surfaces O Frequently used on paper documents O Purple/blue prints will appear w/in 1 to 2 hours after application O Chemical reaction occurs with amino acids in the deposited perspiration

27 Physical Developer O Silver nitrate-based liquid O Used for visualizing latent prints undetected by previous methods O Good for porous materials that may have been wet at one time O Should be the LAST method used O Washes away traces of proteins from an object’s surface O Order of application: Iodine  Ninhydrin  Physical developer

28 Super Glue Fuming O Most useful for nonporous surfaces such as metals and plastics O Process: O Super Glue (cyanoacrylate) heated in enclosed chamber with suspect material O Expose for about 6 hours O Is developed when the glue adheres to the print and gives it a white appearance O Fuming wands are available for more convenient development on larger surfaces O Has been used to develop prints in small, enclosed areas such as the inside of a car

29 Super Glue Fuming

30 Fluorescence O 1 st – Discovered that fingerprints could be visualized by exposure to laser light O 2 nd – Fingerprints could be treated with chemicals that would induce fluorescence when exposed to laser light O Chemicals that could be applied after development (zinc chloride after ninhydrin, rhodamine G6 after Super Glue fuming) O 3 rd – Lasers were no longer needed to induce fluorescence as it was now chemically induced, and high-intensity or alternate light sources could be used to visualize prints

31 High-intensity Alternative light sources O Quartz halogen O Xenon-arc O Focused using fiber- optic cables O Can utilize several filters giving the flexibility to select different wavelengths of light O Light-emitting diodes (LEDs) O More portable

32 Additional Processing Information O Chemical agents do not interfere with DNA tests O Ideally, all processing and development of prints should be done in the laboratory and NOT at the crime scene

33 Preservation of Developed Prints O Once developed, fingerprints must be preserved O Before preservation  fingerprints must be photographed FIRST! O Close-up of fingerprint O Expanded shot for overall location of the fingerprint O 2 possible procedures: O Small objects: O Preserve object w/ print in its entirety O Cover print w/ cellophane O Large objects: O If developed w/ powder, lift print w/ adhesive

34 Digital Imagining For Enhancement O Photographs are turned into digital files O The larger the # of pixels, the more closely the file will resemble the real-world image O Allows for the removal of background color interference O More reliable hits in AFIS O Easy creation of fingerprint comparison charts

35 Digital Imagining For Enhancement


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