JS 112 Fingerprint Lecture and Lab

Transcription

1 JS 112 Fingerprint Lecture and Lab I. Pre-class activities a. Announcements and Assignments II. Learning objectives a. List 3 major fingerprint patterns and respective subclasses b. Name individuals that have made significant contributions to acceptance and development of fingerprints c. Define ridge characteristics d. Explain visible, plastic vs. latent prints e. List techniques for developing latent prints on non porous objects f. Describe chemical techniques for developing prints on porous objects g. Describe the proper procedure for preserving a developed latent fingerprint h. Explain how a latent fingerprint image can be enhanced by digital imaging

2 Announcements and Assignments Assignments/Schedule/Lectures: Read chapter 16 Guest Lecturers Rosa Vega Weds March 17 th Strengthening Forensic Science in the United States: A Path Forward (2009) e=r1 Extra Credit: Write a 100 word summary with 3 Q and 3 answers on any chapter in the NAS report:

3 BASIC PATTERNS 1 2 3

4 8 DIFFERENT TYPES OF FINGERPRINTS Remembered by: L A W

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6 A brief history of fingerprints (1) 1883 The first systematic attempt at personal identification was by Alphonse Bertillon-anthropometry Dimensions of human bone system remained fixed from age 20 to death For 2 decades it remained the most accurate method.

7 A brief history of fingerprints (2) Chinese used to sign legal documents 3000 years ago with fingerprints (ceremonial of for human ID still unknown) In India years before Bertillon, William Hershel started the practice of requiring natives to sign contracts with imprints of their right hands 1880, Henry Fauld working in a Japanese hospital published a suggestion that skin ridge patterns could be important for the identification of criminals Offered to Scotland yard but rejected

8 A brief history of fingerprints (3) 1892 Francis Galton published his classic textbook Finger Prints, - anatomy of fingerprints and suggested methods for recording them. Galton proposed assigning three pattern types: Loops, Arches, and Whorls Book demonstrated that no two prints were identical and that they remained unchanged from year to year 1891 Juan Vucetich created a classification system 1897 Sir Edward Richard Henry created another classification system adopted by US.

9 A brief history of fingerprints (4) 1903, Will West at Ft Leavenworth prison. William West who was already in prison could not be distinguished by anthropometry nor photographs but by fingerprints

10 A brief history of fingerprints (5) 1901, NYC Civil Service commission adopts fingerprints for personal ID to certify all civil service applicants 1904, used at the World s Fair in St. Louis for representatives of Scotland Yard 1924 BI records and Leavenworth records merged forming the nucleus ID records at the FBI where the largest collection now exists Admissibility challenge in US v. BC Mitchell- Eastern PA. Argued, fingerprints could not be proven unique under Daubert. Following 4.5 days, upheld fingerprints as scientific evidence ruled that 1) human friction ridges are unique and 2) human friction ridge skin arrangements are unique and permanent.

11 FINGERPRINT ANALYSIS Most familiar to public Leaving a readable print depends on: - Surface on item touched - Condition of fingers - Way item is handled Fingerprints are completely individual characteristics. First Principle- A fingerprint is an individual characteristic; no two fingerprints have yet been found to possess identical ridge characteristics

12 WHAT ARE FINGERPRINTS? Friction Ridges raised lines on skin that come together to form patterns also known as minutiae Designed by nature to provide our bodies with a firmer grasp and resistance to slippage Second Principle: Patterns formed by ridges never change throughout an individual s life*. Fingerprint remains unchanged during an individuals lifetime * individual marks and scars can be added John Dillenger tried with acid- see figure 14.4

13 WHAT ARE FINGERPRINTS? Third Principle: All prints have ridge characteristics that permit them to be systematically classified % of the population has loops, have whorls and only 5% have arches LAW form the basis for all classification systems Loops- ridge lines that enter from one side and curve around to exit from the same side of the pattern Arch- lines that enter from one side and exit from the other Whorls- ridge patterns are rounded or circular in shape and have two deltas

14 Error Rate What are the chances that two different fingers will have the same friction ridge arrangement? Error rate of methodology? Error rate of practitioner?

15 FBI error in identification and review of latent prints- Coming clean on an error in the application of the method in the Madrid bombing case Stacey, RB A Report on the Erroneous Fingerprint Individualization in the Madrid Train Bombing Case. Journal of Forensic Identification 54 (6) :