Everybody look at your right index finger

Friction ridge analysis

Batman Ballistics

By chemically removing your fingerprints, you become virtually undetectable.

A. TrueB. FalseC. You’ve been watching too

much “Without a Trace”

History of Fingerprints

● Ancient Babylon, China, Persia

● 1686 - Malpighi○ notes ridges, spirals,

and loops● 1823 - Purkinje

○ names 9 patterns● 1958 - Hershel

○ utilized a handprint on a contract

○ criminal database

● 1880 - Faulds○ published in Nature

declaring fingerprints as means of personal identification

● Bertillon○ first scientific method

of identification● 1890 - Galton

○ publishes first book on fingerprints

History of Fingerprints

Faulds sends his paper to Darwin

Darwin sends Faulds’ paper to

Galton

Galton is credited with proving Faulds’ claims

Galton trained under Vucetich

Vucetich made the first criminal fingerprint

identification in 1892

Faulds’ claims:1. No two

fingerprints are exactly the same

2. Fingerprints do not change over the course of a person’s life

Rojas Murders

Anthropometry/Bertillionage

Defined: the study of human body measurements to be used for classification and measurement

● in the 19th and 20th centuries, it was used to classify criminals

● made famous by Alphonse Bertillon

Biometrics: use of measurements of portions of complex patterns from the human body to build a database that can be used to “verify” the “identity” of persons within that database

it worked until it didn’t

Will West

William West

fingerprints

Fingerprints

Latent prints:friction ridge impressions that are not visible to the unaided eye; consist of a mixture of natural secretions (98-99% sweat, oil)

patent prints: impressions of friction ridges which are visible to the unaided eye in media such as oil, blood, ink, or mud

Friction Ridges● Swellings on the fingertips begin

at 6.5 weeks● Shape of the volar pad and

resulting ridge patterns are due to genetics, physical influences and stresses in the womb

● At about 10-13 weeks, ridge patterns begin to develop. Volar pads begin to reduce in size until their boundaries and the surrounding skin merge

Friction Ridges

● The ridge arrangement on every hand and foot of every person is different

● What makes friction ridge patterns useful?○ Permanence and

Uniqueness

Anatomy of a scar

Can you alter your fingerprints?

in the 1930s, John Dillinger put acid on his fingertips but did

not destroy his ridges completely.in most cases, the act of alteration makes the prints

easier to identify by adding cuts/scars

to the ridge structure.

Friction Ridges

● definitively develop on fetus pre-birth

● persistent during life except for permanent scarring

● details are unique and never repeated

● overall patterns may vary within limits allowing for classification

Fingerprints

Classification System

inclusionexclusionCLASS

characteristics

Fingerprints

Identification: matching points of minutiae

INDIVIDUAL characteristics

Minutiae: features of the friction ridge skin patterns on fingertips that make the overall pattern individual

Points of minutiae

INDIVIDUAL characteristics

Minutiae diagram:a and b: Bifurcationsc: Enclosured and e: Ending ridgesf: Island(Reprinted from Galton (1892))

Points of minutiae

INDIVIDUAL characteristics

It is possible to recover a print from the sticky side of

duct tape.

A. TrueB. FalseC. You’ve been watching too

much NCIS

Video: Developing latent fingerprints on the adhesive sides of tape

Fingerprint Processing1. Visual

Examination or Search

2. Enhancement or

Visualization

3. Photography

4. Lifting or collection of

object 5. Laboratory analysis or comparison

Chemical Enhancements for Fingerprints

Cyanoacrylate(that’s superglue)● prints are fumed

with cyanoacrylate● then powdered to

visualize

Chemical Enhancements for Fingerprints

Ninhydrin● sprayed on latent

prints● heated to visualize

Which provides a macroscopic perspective?

A. Alternate Light source (ALS)

B. Magnifying glass

Which is a class characteristic?

A. BifurcationB. Whorl

Which type of print is visible without any additional enhancement or aid?

A. latentB. patent

Identification

Scientific Method

Identification depends on pattern matching points of minutia

Analysis - evaluate Level 1, 2, & 3 minutiaeComparison - determine agreement and discrepanciesEvaluation - cyclical procedure of evaluationVerification - 2nd examiner

ACE-V is the fingerprint discipline’s scientific method

Fingerprints

skin

slippage

Recovery of prints from deceased victim

Recovery of prints from deceased victim

Levels of Detail

Level 1:general ridge flow

and pattern configuration

Level 2:ridge endings,

bifurcations, dots, and combinations

Level 3:ridge detail

including pores

NOT sufficient for individualization, can be used for exclusion

sufficient for individualization

Fingerprints

Automated Fingerprint Identification System

AFISOperates by anchoring position of fingerprint and searching database using two types of ridges:•Bifurcations•Ridge endings

Database works by querying prints to find ones with same number of ridges in relative positionsMost likely matches are displayed for comparison by a fingerprint examiner

Which is more individualizing?

A. ridge endingB. loop

Identical twins have the same fingerprints.

A. TrueB. False

Do identical twins have the same DNA?

A. YesB. No

Old 10 print card

revised 10 print card

NCIS Abby clip