1. Fingerprinting (latent) Biotechnology II

2. Skin Layers Epidermis: superficial layers of keratinized stratified squamous epithelium

3. Layers Dermis: deeper than epidermis; sheet of irregular fibrous dense connective tissue Responsible for most of the structural strength Blood vessels supply dermis and epidermis Contains sensory nerve endings which are responsible for sensations such as hot and cold

4. Layers: Dermis continued Papillary layer: bumpy superficial portion of dermis attached to the epidermis. Papillae form regular rows in thick skin but are irregularly arranged in thin skin. This is why fingerprints and the soles of your feet have distinct ridges. These ridges also help with our ability to grip things.

5. Structure of Skin Did you know… stretch marks develop from a rupture in the dermis and the epidermis is not effected.

6. Hair Did you know… Hair is present on all skin surfaces except the palms, soles, lips, etc. Hair follicle extends from surface into the dermis and contains a hair root Hair shaft protrudes above the surface of the skin

7. Fingerprints History Japanese used thumb print as a signature on documents until 1860. First used in crime in 1901 by Sir Edward Richard Henry 3 Patterns Whorl Loop Arch

8. Fingerprints Most natural finger prints consists of secretions of the skin’s glands 3 Glands Eccrine: secretes H 2 0 and inorganic & organic contaminants Sebaceous: secretes fatty acids and hydrocarbons Apocrine: secrete cytoplasm and nuclear materials such as carbohydrates

9. Fingerprints: Interesting Facts Fingerprints are completely formed before birth Genes determine finger prints but there can be slight differences between identical twins due to slight movement during development. Yes, you can burn them off with acid BUT they will reform in exactly the same pattern you were born with Ridge pattern never changes even as you get older.

10. Latent fingerprints Fingerprints left behind at a crime scene May or may not be visible Visible usually have blood, grease, dirt, etc. in them to display the background Non visible need treatment “latent print development” to be seen

11. Methods of Detection Types of prints Latent print Visible print – deposited ink, blood, dirt Plastic print – impression in a soft surface Locating prints – RUVIS

12. Categories of Fingerprints Loop – ridge lines enter one side of pattern and curve around to exit from the same side of pattern. (65%) Ulnar loop – opens toward little finger Radial loop – opens toward thumb Ulnar LoopRadial Loop

13. Categories of Fingerprints Whorl – ridge lines rounded or circular and have two deltas(30-35%) Plain whorl Central pocket loop Double loop Accidental loop

14. Categories of Fingerprints Arch – ridge lines enter print from one side and exit from the other (5%) Plain Tented

15. Developing Prints Powders Charcoal Magnetic Fluorescent Chemicals Iodine fuming (sublimation) Ninhydrin Physical developer (silver nitrate) Super Glue fuming Alternate Light Sources/ LED

16. Preservation of Developed Prints Photographs Print surface should be removed in its entirety (covered with cellophane) Lifted from surface with tape Digital imaging into pixels – allows adjustments to be made to enhance picture

17. Classification of Fingerprints Henry system – numerical system involving the presence or absence of the whorl pattern on each finger as part of the primary classification.. This does not identify someone, only reduce the number of possible candidates AFIS – 10 print system that can search 500,000 stored ten-prints in 0.8 seconds Data entered now by Livescan rather than ink rolling. Human decisions must still be made Software incompatibilities among states