Monday, 12/1Homework: Bring 1 to 2 aluminum cans for ThursdayAgenda for today: Lecture on history of fingerprints, types of prints, and visualization of prints.
History of Personal Identification
O The Bertillon System was the 1st attempt at a personal identification systemO Introduced by French police expert Alhonse
Bertillon in 1883O Relied on a detailed description (portrait
parle) of the subject, combined with full length and profile photographs and system of precise body measurement (anthropometry)
AnthropometryO 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 recommendedO Height, reach, width of head, length of left
foot
A Bertillon "booking" Card
Bertillon Fingerprint Card
Henry FauldO Scottish PhysicianO 1st person to realize the potential application
of fingerprinting to personal identificationO 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.
Sir Francis GaltonO 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 1892O 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”.
Juan VucetichOArgentine Police OfficialO1891: began the first fingerprint files
based on Galton pattern types – still used in some S. Am countries today
O1892: 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.
Juan Vucetich
Sir Edward Richard HenryO Developed another classification
system for fingerprints in 1901O Scotland Yard adopted the Henry
system in 1901O 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
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.
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
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.
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
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
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
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.
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
Locating Fingerprints
O The method of visualization is determined by the type of surface being examined:O Hard/nonporous surfaces: Powders and
Super Glue fumingO Soft/porous surfaces: Chemical treatment
O RUVIS (Reflected Ultraviolet Imaging System)O Aims UV light onto a non-absorbent surface
to help locate fingerprintsO Prints are then developed in the
appropriate manner
List the techniques for developing latent fingerprints on porous and non-porous surfaces.
O Powders (grey/black, metallic, fluorescent)
O Chemical methods:O Iodine fumingO NinhydrinO Physical developerO Super Glue fumingO DFO
O Fluorescence
PowdersO Used mostly on dry, nonporous surfacesO Applied with camel’s hair or fiberglass brushO Powders adhere to the perspiration and oil
residues left by the ridgesO Grey/black:
O Most commonO Used on lighter surfaces
O Magnetic:O Less damaging to printO Good for leather and rough plastics
O Fluorescent:O Used in conjunction with UV lightO Prevents prints from being obscured by color of the
surface
Iodine FumingO Oldest of the chemical methodsO Process:
O Iodine crystals and suspect material placed in a cabinet and heatedO Iodine goes directly from solid crystals to a gas
(sublimation) when heatedO Vapors combine w/ the print to make it visibleO 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 permanentO Can be extended by a month to a year with the
application of a 1% solution of starch in water
NinhydrinO Process:
O Sprayed onto porous surfacesO Frequently used on paper
documentsO Purple/blue prints will
appear w/in 1 to 2 hours after application
O Chemical reaction occurs with amino acids in the deposited perspiration
Physical DeveloperO Silver nitrate-based liquidO Used for visualizing latent prints
undetected by previous methodsO Good for porous materials that may have
been wet at one timeO 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
Super Glue FumingO Most useful for nonporous surfaces such as
metals and plasticsO Process:
O Super Glue (cyanoacrylate) heated in enclosed chamber with suspect material
O Expose for about 6 hoursO Is developed when the glue adheres to the
print and gives it a white appearanceO Fuming wands are available for more
convenient development on larger surfacesO Has been used to develop prints in small,
enclosed areas such as the inside of a car
Super Glue Fuming
FluorescenceO 1st – Discovered that fingerprints could be
visualized by exposure to laser lightO 2nd – Fingerprints could be treated with
chemicals that would induce fluorescence when exposed to laser lightO Chemicals that could be applied after
development (zinc chloride after ninhydrin, rhodamine G6 after Super Glue fuming)
O 3rd – 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
High-intensity
Alternative light sources
O Quartz halogenO Xenon-arcO Focused using
fiber-optic cablesO Can utilize several
filters giving the flexibility to select different wavelengths of light
O Light-emitting diodes (LEDs)
O More portable
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
Preservation of Developed Prints
O Once developed, fingerprints must be preserved
O Before preservation fingerprints must be photographed FIRST!O Close-up of fingerprintO Expanded shot for overall location of the
fingerprintO 2 possible procedures:
O Small objects:O Preserve object w/ print in its entiretyO Cover print w/ cellophane
O Large objects:O If developed w/ powder, lift print w/ adhesive
Digital Imagining For Enhancement
O Photographs are turned into digital filesO 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 AFISO Easy creation of fingerprint comparison
charts
Digital Imagining For Enhancement