Presentation is loading. Please wait.

Presentation is loading. Please wait.

Development of fingerprinting What did Sir Francis Galton discover in the 1800s? Ridge characteristics, or “Galton points.” What are they? Different formations.

Similar presentations


Presentation on theme: "Development of fingerprinting What did Sir Francis Galton discover in the 1800s? Ridge characteristics, or “Galton points.” What are they? Different formations."— Presentation transcript:

1 Development of fingerprinting What did Sir Francis Galton discover in the 1800s? Ridge characteristics, or “Galton points.” What are they? Different formations of lines on a fingerprint Examples? Line endings, dots, islands, bifurcations Copyright © 2010 Christine Beck Lissitzyn

2

3 Class vs. Individual characteristics What elements of fingerprints are class characteristics? Loop, whorl, and arch. Why? Because 60% of people have loops, 35% have whorls and only 5% have an arch. If all you can identify is one ridge ending, is it a class or individual characteristic? Copyright © 2010 Christine Beck Lissitzyn

4 Declaring a “match” What is the ACE-V process? Analysis—broad review to check quality, one print; often used to exclude Comparison – compare ridge characteristics to eliminate or include; quantitative likeness Evaluation – done visually; qualitative likeness Verification – process repeated by another technician. Copyright © 2010 Christine Beck Lissitzyn

5 Red Flags What are red flags in the Analysis process? See Plaza I. Fat ridges – may be two overlapping Different amounts of pressure Similar ridge characteristics close to each other – may be “double tap.” “shadow ridges” in furrows – may mean two prints deposited Copyright © 2010 Christine Beck Lissitzyn

6 Madrid bombing latent print Copyright © 2010 Christine Beck Lissitzyn

7 Comparison stage, p. 144 How did this differ in 1973 compared with the AFIS system? What does the computer do? Circle ridge characteristics and mark direction with tail. Locate the “center” and “delta.” Add number of circled characteristics Give “ridge count,” number of ridges between each identified Create a “map” of the characteristics Copyright © 2010 Christine Beck Lissitzyn

8 What does the examiner do? Eliminate some ridge characteristics Reposition some tails Tell the computer if he is sure what finger it is Visually check the computer results against the prints it identifies Declare an opinion Copyright © 2010 Christine Beck Lissitzyn

9 What opinions can the examiner give? Identification Elimination Inconclusive Copyright © 2010 Christine Beck Lissitzyn

10 What are the subjective elements? What does subjective mean? Examiner uses training and experience to make judgments about: How many prints are in latent print Red flags – not one print Whether AFIS has correctly identified a ridge char. Whether a top candidate can be eliminated due to place or circumstance. Copyright © 2010 Christine Beck Lissitzyn

11 Is the first candidate always the match? Chris Grice says 75% of the time. Is the candidate with a score of 1,000 necessarily a match? Copyright © 2010 Christine Beck Lissitzyn

12 Fingerprints and Daubert Why did State v. Abreu decide fingerprinting id. met Daubert? Because the judge held it was generally accepted. What did the court say on p 148? “the court has wide latitude in deciding how to determine reliability....[it] did not clearly err in giving greater weight to the general acceptance factor. Copyright © 2010 Christine Beck Lissitzyn

13 Madrid prints Copyright © 2010 Christine Beck Lissitzyn

14

15 Would Grant be convicted without the Fingerprint? DNA? If Grant won his appeal, the state would not be able to use the DNA. If the court had required the jury to find the fingerprint could only have been left at the time of the crime beyond a reasonable doubt? What was the corroborating evidence to the fingerprint? Copyright © 2010 Christine Beck Lissitzyn

16 The full set of PowerPoint slides is available upon adoption. Email bhall@cap-press.com for more information.


Download ppt "Development of fingerprinting What did Sir Francis Galton discover in the 1800s? Ridge characteristics, or “Galton points.” What are they? Different formations."

Similar presentations


Ads by Google