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Ridgeology

Ridgeology. A Closer Look at Fingerprints. T. Trimpe 2007 http://sciencespot.net/. Image from ftp://sequoyah.nist.gov/pub/nist_internal_reports/ir_6534.pdf.

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Ridgeology

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  1. Ridgeology A Closer Look at Fingerprints T. Trimpe 2007 http://sciencespot.net/ Image from ftp://sequoyah.nist.gov/pub/nist_internal_reports/ir_6534.pdf

  2. As we have learned in our first lesson, a fingerprint is made of a series of ridges and valleys on the surface of the finger. The uniqueness of a fingerprint can be determined by the pattern of ridges and valleys as well as the minutiae points, which are points where the ridge structure changes. Did you know? The koala is one of the few mammals (other than primates) that has fingerprints. In fact, koala fingerprints are remarkably similar to human fingerprints; even with an electron microscope, it can be quite difficult to distinguish between the two. Ridgeology: The study of the uniqueness of friction ridge structures and their use for personal identification.1 The Concept of studying ridges was first discovered by Dr. Edmond Locard, later to be termed Ridgeology by DavidAshbaugh 1Introduction to Basic Ridgeology by David Ashbaugh, May 1999 Image from http://www.cs.usyd.edu.au/~irena/minutia.gif

  3. Ridge Characteristics Use these characteristics as points of identification when comparing fingerprint samples. The more points you can find in common, the better the match!

  4. Crossover Core Bifurcation (fork) Ridge ending Scar Island Delta Pore Ridge Characteristics EXAMPLE http://cnx.org/content/m12574/latest/properties.jpg

  5. http://www.dkfz.de/tbi/projects/bmcv/images/iu_it246_04s_fingerprint1.jpghttp://www.dkfz.de/tbi/projects/bmcv/images/iu_it246_04s_fingerprint1.jpg How many ridge characteristics can you identify in this fingerprint?

  6. Automated Fingerprint Identification System (AFIS) AFIS is a computerized system capable of reading, classifying, matching, and storing fingerprints for criminal justice agencies. Quality latent fingerprints are entered into the AFIS for a search for possible matches against the state maintained databases for fingerprint records to help establish the identity of unknown deceased persons or suspects in a criminal case. http://www.fdle.state.fl.us/CrimeLab/images/fingerrint%20comparison%20for%20afis.jpg Fingerprint Identification When minutiae on two different prints match, these are called points of similarity or points of identification. At this point there is no international standard for the number of points of identification required for a match between two fingerprints. However, the United Kingdom requires a minimum sixteen points while the United States and Australia only requires twelve. AFIS Video Link: https://www.youtube.com/watch?v=ZKi1CKTRCQM

  7. Fingerprint Identification 8. For almost a hundred years, the primary method used to examine prints was the point system. An examiner would compare the ridges in two prints, and if enough of the ridge points matched, anywhere from twelve to sixteen, then there was said to be an identification. 9. In the past ten years, there has been a shift away from the points system to the system known as “ridgeology”.1 An examiner must determine if there are enough features (not just points) in common to determine if two fingerprints are matches. Possible features to consider in identification: • Overall ridge pattern • Individual ridge patterns (ridge ending, bifurcation, dot, etc.) • Individual ridge structures (width, shape, position of pores, etc.) • Other features present in a print, such as creases, scars, warts, etc. Source: http://www.abc.net.au/rn/bigidea/stories/s673661.htm

  8. Try It! 1 – Blow up your balloon about halfway and twist the end to keep the air from coming out. Do not tie it off! 2 – Use an ink pad to make a print with your thumb and write your name on the balloon as well. 3 – Blow up the balloon to full size and tie the end. 4 – Analyze the fingerprints to find several ridge structures that we have discussed. Use a marker to mark these structures on your balloon Think About It! Which ridge structures were most common in your fingerprints? Which ridge structures were most common in your group? Were there any structures that were not found in any of the fingerprints? Balloon Fingerprint Activity: http://www.msichicago.org/fileadmin/Education/learninglabs/lab_downloads/fingerprint_analysis.pdf

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