1. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com

2. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com What are Fingerprints? If a finger touches a surface, perspiration and oils from the body are transferred onto the surface, leaving an impression of the finger’s friction ridge patterns. Fingerprints may contain traces of any material found in perspiration including DNA and chemicals such as nicotine.

3. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com What are Fingerprints? Friction ridges are found on skin in the following regions: –Palms of hands –Palmar aspect (palm-side) of fingers –Soles of feet –Solar aspect (sole-side) of toes They exist to give firmer grip and resistance to slippage. The number of ridges and their shape is largely determined by genes.

4. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Skin Surface Outer surface layer of skin is the epidermis. The inner layer of skin is the dermis. Between these two are the dermal papillae. The papillary pattern determines the form and pattern of the friction ridges on skin surface.

5. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Skin Surface Each skin ridge is populated by a single row of pores that are openings for ducts leading from the sweat glands. Perspiration is released and deposited on the surface of the skin through these pores.

6. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Fingerprints are Unique Dermatoglyphics is the study of fingerprints. No two fingers have yet been found to have identical ridge characteristics (minutiae). Ridge pattern remains unchanged throughout life.

7. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Fingerprints do not Change Friction ridge pattern of skin develops in utero (before birth) due to uneven stresses in the different layers of the developing skin. Identical (monozygous) twins –have the same DNA. –have different fingerprints.

8. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Intentionally Altering Fingerprints Very difficult to do, but there has never been a lack of trying. –Bank robber John Dillinger attempted to burn off his fingerprints with corrosive acid. They grew back. –Illegal immigrants and criminals sometimes undergo finger print plastic surgery. They can still be identified by palm prints and DNA. To change the pattern requires obliteration of the dermal papillae (1- 2 mm deep). Attempts to destroy the pattern can backfire and cause more unique details!

9. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Types of Fingerprint Patterns There are 3 basic fingerprint patterns –loops (60-65% of population) –whorls (30-35%) –arches (5%)

10. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Loops Have ridges entering from one side of the print, turning, and leaving from the same side. The pattern area of the loop is surrounded by two diverging ridges known as type lines. The approximate center is called the core. The ridge point nearest the type line divergence is known as the delta (capital greek letter Δ).

11. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Loops 65% of the population have loops. All loops must have one delta. If the loop opens toward the little finger then it is a ulnar loop. If the loop opens towards the thumb then it is a radial loop.

12. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Arches In an arch, ridges enter from one side of the print and exit on the opposite side.

13. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Arches Arches are divided into two distinct groups: –plain arches –tetrarches or tented arches The tetrarch consists of an upthrusted ridge in the center of the arch.

14. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Whorls All whorl patterns must have a core and at least two deltas

15. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Special Loops The double loop is made up of two loops combined into one fingerprint. The pocked loop has a small circle at the core.

16. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Other Patterns An accidental pattern contains two or more patterns, but not the plain arch, and is not covered by other categories. It may consist of a combination loop and plain whorl or loop and tented arch.

17. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Types of Prints Latent: hidden or invisible –Made by natural body secretions of the hands and fingers (perspiration & grease) –Requires dusting or other method to make visible Patent: visible to the naked eye –Blood, ink, dirt, glass Plastic: a 3-D fingerprint –Wet paint –Soft material like clay

18. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Impressions and Prints Impression –3-D –in soft surface –often visible Print –2-D –transfer of skin perspiration, oils, or a foreign substance –usually latent

19. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Powder Techniques Used on non-absorbent surfaces Tipped or very softly brushed on Various types Black powder (carbon) Grey powder (Aluminum dust) Magnetic-Sensitive Powder (Magnabrush) Fluorescent Powder (seen in UV light)

20. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Using Powder with a Brush Powder is brushed on carefully with a twirling motion. The excess powder is removed with the brush or a puffer bulb. Prints are photographed in place before lifting. Lift the print with broad adhesive tape. Transfer the print by sticking tape onto a card or lifter.

21. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Chemical Techniques Iodine Fuming Ninhydrin DFO Silver Nitrate Physical developer Super Glue Fuming

22. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Iodine Fuming Oldest technique for latent prints Iodine crystal sublimes in Fuming Cabinet Iodine reacts with fatty oils or perspiration (salts) Print fades rapidly Fixed by spraying with starch solution (blue)

23. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Ninhydrin Ninhydrin (triketohydrindene hydrate) For latent prints on paper & porous surfaces Interacts with amino acids in proteins in fingerprints Easy to use & sensitive Sprayed on Prints appear in 1-2 hours, weak prints in up to 48 hours, hastened by heat.

24. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Silver Nitrate For Porous surfaces –paper, wood, cloth, brass Article sprayed, brushed or dipped with the solution AgNO 3 + NaCl AgCl + NaNO 3 AgCl is photosensitive, turns dark brown in daylight or UV. Blurs with time, recorded by photography

25. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Superglue Fuming Cyanoacrylate ester (Super Glue) Fuming by heat or NaOH in cabinet Fuming wand for use at scene (inside a car) Non-porous surfaces –metal, tape, leather, plastic White prints appear in a few hours

26. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Fluorescence Techniques Argon-ion Lasers Alternate Light Sources Colored filters & goggles required Natural fluorescence by components of perspiration and blood Fluorescent powders Fluorescent dyes –ninhydrin + ZnCl Superglue + Rhodamine

27. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Classification Systems Once fingerprints are recorded, a system is required to describe and place them in logical order. The most prominent system used before computer analysis was the Henry System created by Sir Edward Richard Henry and Azizul Haque in the late 19 th century. The Henry System is still included as part of many electronic systems and taught by the FBI.

28. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System The fingerprint records in this system are classified by broad characteristics. This system reduces the effort needed to search through vast fingerprint collections. All 10 fingers are put into groups of 2 with numerical weights assigned to each group

29. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number12345678910 Value if whorl is present 16 88442211

30. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System Each fingerprint is then analyzed. If a whorl is present the value is recorded for that fingerprint. If a whorl does not exist then zero is recorded for that fingerprint

31. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number12345678910 Value if whorl is present 16 88442211 Example No 0 Yes 16 No 0 Yes 8 No 0 No 0 Yes 2 No 0 No 0 Yes 1

32. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System Next, the Henry Classification Formula is used to find the grouping ratio. The grouping ratio is a unique identifier for categorizing the particular type of fingerprint that the person has.

33. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System The Henry Classification Formula is: The grouping ratio cannot be simplified. For example, 32/32 and 1/1 are both unique ratios.

34. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number12345678910 Value if whorl is present 16 88442211 Example No 0 Yes 16 No 0 Yes 8 No 0 No 0 Yes 2 No 0 No 0 Yes 1

35. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Fingerprint Points The individuality of a fingerprint is determined by a careful study of its ridge characteristics (points). Specific traits found in friction ridges are used to establish an identification by their relative location to each other. The average finger has between 75 and 175 points of identification. The palmar area has over 2000 points of identification.

36. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Types of Points

37. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Matching Points For two points to match they must be at the same location on the fingerprint be the same type. At crime scenes only partial prints are usually recovered, therefore a small number of ridge characteristics may be compared. 16 matching characteristics have been suggested to establish the uniqueness of a print.

38. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Fingerprint Records Originally, fingerprint records were made with ink on paper cards. Finger prints were rolled in ink and 4-finger and 2-thumb flat impressions were collected. Cards can be scanned into modern databases. The demand for improved systems and digital records has created a movement toward scanning to replace ink.

39. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com IAFIS Integrated Automated Fingerprint Identification system (IAFIS) is used by the FBI to store digital prints. It is the largest biometric database in the world, containing records for more than 100 million people. When the automated process is finished the system generates a “hit” list –Possible matches then checked by expert –New original prints obtained for checking

40. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com What is included in IAFIS? Each record may include: –Criminal history –Fingerprints –Mug shots –Scars and tattoos –Physical characteristics height, weight, aliases, hair and eye color, race

41. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com Who submits data to IAFIS? The system includes civil fingerprints, mostly of individuals who have served or are serving in the U.S. military or have been or are employed by the federal government. The fingerprints and criminal history information are submitted voluntarily by state, local, and federal law enforcement agencies. Employment background checks, some firearms purchases, and the US-VISIT program also provide information to the system.

42. Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. www.CrosscuttingConcepts.com