Fingerprint Analysis
Francis Galton Established that no two prints were _____________ Noticed 3 patterns: 1. 2. 3. identical Loops Arches Whorls
Fingerprint Principles 1. Are ____________ characteristics. 2. Remain __________ for life. Change by scarring 3. Ridge patterns that allows them to be _________ individual unchanged identified
Types of Prints Latent Prints Fingerprint made by the deposit of _____ and/or _________ _________ easily see this type of print. oil perspiration Can’t
Types of Prints Visible Prints Made when the finger deposits ____________ onto a surface Ex. ____________ Plastic Prints Fingerprint impressed in a ______________ visible material Ink, blood soft surface
Dermal Papillae Determine the structure of our ______________ The ridges allow for a __________ and resistance to _________ If this layer is damaged __________ ridge characteristics firm grip slippage It is totally impossible to oliterate all of the ridge characteritics on the hand. The presence of permanent scars provides new characteristics for identification scars form
Destruction of Fingerprints __________ Skin grows back Scarring makes ________________ Can’t be done them more unique
John Dillinger Tried to get rid of his own fingerprints with acid But it did not work Tried to get rid of them
Fingerprint Patterns Left Hand
Arches opposite sides Ridges enter and leave from __________________ sides. Tented Arches Spike or “tent” Plain Arch
Radial and Ulnar Loops delta the same side Radial Loop VS Have one ______ Enter and leave the print from______________ delta the same side Delta Radial Loop opens toward the radius/thumb Ulnar Loop Opens toward the ulna/pinkie VS
Radial vs Ulnar Loops
Whorls deltas Have at least two ______ Plain Whorl Central Pocket Whorl Double Loop Whorl Accidental Whorl Delta “Ying yang” Does not fall under other patterns
Identify the Pattern
Identify the Pattern
Identify the Pattern
Identify each fingerprint pattern. ? A B Right Hand Left Hand Answer Key: A - Plain Whorl, B – Double Loop Whorl, C – Radial Loop, D – Tented Arch, E – Plain Arch C Right Hand E D Right Hand Left Hand
It’s time to make some prints! Avoid Partial Prints GOOD PRINT Get as much of the top part of your finger as possible!
Directions 1st – Roll the “pad” portion of your thumb over the ink pad from the left side of your thumb to the right. You do not have to push down really hard! 2nd – Roll the “pad” portion of your thumb from the left side of your thumb to the right in the correct box on your paper to make a thumbprint. 3rd – Continue this process to make a fingerprint of all ten fingers on the “My Prints” worksheet. 4th –Use your notes and a magnifying lens to help you figure out what type of pattern is found in each of your fingerprints. Label each one with the pattern’s name.
Fingerprint Identification Matching of prints Ridge characteristics on ______________ prints match No set standard for number of _______ two different matches
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!
Ridge Characteristics Crossover Core Bifurcation (fork) Ridge ending Island Delta Pore Scar EXAMPLE http://cnx.org/content/m12574/latest/properties.jpg
Identify . . . . http://www.dkfz.de/tbi/projects/bmcv/images/iu_it246_04s_fingerprint1.jpg
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One more time . . . .
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AFIS Fingerprint ______________ database Matches prints ______________ World wide
Developing Latent Prints https://www.youtube.com/watch?v=tqFzVfPRd5s