Unit 4 Fingerprint Identification

1. Students will explore fingerprint identification Unit 4 Fingerprint Identification

2. Labs • 1. Latent Prints: five parts • Dusting • Iodine • Superglue fuming • Ninhydrin • Silver nitrate • 2. Plastic Prints: cast & mold a print • 3. Visible Prints: photography

3. Vocabulary • Latent print • Visible print • Plastic print • Iodine fuming • Super glue fuming • Ninhydrin • Physical developer • Epidermis • Dermis • First Principle • Second Principle • Third Principle • IAFIS • Ten Print System • First Degree ID • Second Degree ID • Third Degree ID

4. FUNDAMENTAL PRINCIPLES OF FINGERPRINTING • First Principle: A fingerprint is an individual characteristic, no two fingers have identical ridge characteristics • It is not the shape of a print that is individual, but the number, location and shape of specific ridge characteristics • Specific ridge characteristics are called minutiae

5. FUNDAMENTAL PRINCIPLES OF FINGERPRINTING • Second Principle: A fingerprint will remain unchanged during an individual’s lifetime • A fingerprint can be obscured by deep tissue damage such as scars or burns • Scars may be useful as points of identification

6. FUNDAMENTAL PRINCIPLES OF FINGERPRINTING • Third Principle: Fingerprints have general ridge patterns which permit them to be systemically classified. • Classifying the general pattern of fingerprints allows them to be stored in a filing system, which then can be retrieved for comparison. • Modern technology allows this process to be transformed to a computer system- IAFIS

7. Fingerprints: • 19thcentury dactylscopy, or the study of fingerprints began. • Intergrated AFIS (IAFIS) was developed by the FBI to incorporate a variety of programs and search options when using the program.

8. Classification of Fingerprints and Ridge Patterns • Fingerprints can be classified into three basic patterns, loops, whorls and arches

9. Activity • Print on a balloon. Refer to this print throughout the lecture on print patterns and minutiae.

10. LOOPS • Most common pattern, with 65% of all fingerprints having loops • Fingerprint pattern with one or more ridges entering from one side, curving, then going out from the same side entered

12. LOOPS • Loops have two focal points, delta and core • Delta- triangular area found in all loop and whorl patterns • Core- area found near the center of all loop and whorl patterns

14. LOOPS • There are two subgroups to the loop, the radial loop and the ulnar loop • Radial loop- ridges flow in the direction of the thumb ( radius) • Ulnar loop- ridges flow in the direction of the • little finger (ulna) • European ancestry tend to have more loop patterns on their fingerprints

16. WHORLS • Second most common pattern, occurring in 30-35% of all fingerprints • Fingerprint pattern with at least two deltas and a core. Whorls take the form of a spiral, shell, circle, target or eye.

17. WHORLS • There are four types of whorls • Plain • Double whorl- • Central Pocket- • Accidental • Asian and Oriental ancestry tend to have more whorls patterns on their fingerprints.

20. ARCHES • Arches are the least common and the simplest of fingerprint patterns, occurring in 5% of fingerprints • Fingerprint pattern that has no delta or core. All ridges enter one side and exit the other.

21. ARCHES • Arches are subdivided into two distinct groups, plain and tented • Plain-Ridges tend to rise in the center of the pattern, forming a wave-like pattern • Tented – contain a sharp spike in the ridges, or the ridges meet at an angle less than 90 degrees. • African American ancestry tend to have more arch patterns on their fingerprints.

22. Arches

24. 10 Print Classification • Developed by Edward Henry and modified by the FBI. • Breaks up all possible sets of fingerprints to be divided into a possible 1,024 groups. • Based on a whorl pattern

25. 10 Print Classification • Formula: Top: Rt index(16)+ rt ring(8)+ Left thumb(4)+ Left middle(2) + left little(1) + 1 = Bottom: rt thumb (16)+ rt middle (8)+ rt little(4) + left index(2)+ left ring(1) + 1 = • What would a person with a score of ½ have in terms of whorls? • Therefore, if a whorl pattern is present on any of the fingers, it is assigned a numerical value. • Each side of the fraction has a “1” added so there are no zeros

26. 10 Print Classification • Use the formula to calculate your 10 print number. It is a fraction. • The fraction is called your primary classification. This is the first degree of identification. • Second degree is the identification of minutiae • Third degree is the identification of pores

27. Ridge Count • One way to start to individualize prints is to do a ridge count. A straight line is drawn from the central focus to the center of the delta. The number of ridges this line crosses is counted and that number = the ridge count • This works best with loops and whorls where deltas are clearly present.

28. Individualization- Ridge Classifications • To individualize fingerprints you must use the fine structure of ridge characteristics, or minutiae. • There are several classes of minutiae to help individualize fingerprints. • For each type, refer to your balloon print and find one example of each type • Bifurcation- occurs when a ridge splits or forks into two separate ridges

29. Individualization- Ridge Classifications • Double bifurcation-occurs when a ridge splits or forks into two separate ridges, and then splits again into two separate ridges • Ridge End - abrupt termination of any ridge. • Lake or enclosure -occurs when a single ridge line bifurcates, then quickly reconnects and continues as a single ridge

32. Individualization- Ridge Classifications • Island or eye - short ridges that simply start and stop and don’t connect to any other ridge • Dot - a very short island, of basically equal length and width • Bridge -short ridge that runs between two other parallel ridges, sometimes called a “railway tie”

33. Individualization- Ridge Classifications • Spur- a special bifurcation where one resulting ridge is considerably shorter, ending near the original split/fork

35. Identifying Fingerprints • Sir Edward Henry developed a ten print system to classify fingerprints and use them for identification. • The first step is to identify the presence of any whorl patterns, the type of whorl, the number of whorls, etc. The whorl pattern is given a number based on which finger it is on. That number will be set up as a fraction • Each response generates a number in the examiner’s code and each numerical response can be translated to a set numerical description.

36. Identifying Fingerprints • The complete code exactly describes the print in a way people and machines can understand • This presents examiners with a manageable list of possible matches for the fingerprint. • Computer matching of fingerprints is used to make the first big cut of matches, after this manual comparison may still be needed.

37. Go to Forensic Science book, page 54, or refer to slide #25 • Complete your fingerprinting with graphite & tape & a piece of computer paper. Obtain one clear print for each finger. • 1. Labe each finger as loop (& type), whorl (& type) or arch (& type) • 2. Complete your primary classification • 3. Find 10 individualized points of reference on each print. Label each

38. Identifying Fingerprints • There are no legal requirements in the United States on the number of minutiae and their relative location (points) that must match before deciding that a fingerprint belongs to a certain individual. There are 150-200 minutiae in a properly rolled print. Criminal courts will generally accept 8-12 points of similarity as sufficient proof. An newer acceptance level of 10 is typical.

40. Tru TV fingerprint game • http://www.trutv.com/shows/forensic_files/games/fingerprint/index.html

41. AFIS • The Integrated Automated Fingerprint Identification System (IAFIS) is a national automated fingerprint identification and criminal history system maintained by the Federal Bureau of Investigation (FBI). IAFIS provides automated fingerprint search capabilities, latent searching capability, electronic image storage, and electronic exchange of fingerprints and responses. • When a fingerprint has been found at a scene of a crime it is first classified. On the basis of this classification a "short list" of similar fingerprints from the files are compared with the print from the crime scene to try and establish a match, and therefore a identify a possible suspect.

42. AFIS • A photograph of the print from the crime scene is scanned into a computer using  image digitizing software. Using sophisticated software the image of the fingerprint is compared with the computerized database of prints and a list of possible "hits" is produced. It is then up to the fingerprint expert to make the final decision as to whether there is match or not. • This approach has revolutionized criminal investigative used of fingerprints. A computer can make thousands of comparisons in a second, thus increasing the chances of finding a match in a far shorter time than was previously possible. Shortly after being brought on-line for the first time in 1985 the Los Angeles Police Department's AFIS helped bring to justice the multiple killer known as the Nightstalker.

43. AFIS • The device used for scanning live fingerprints into AFIS is called Live Scan. The process of obtaining the prints by way of LiveScan employs rolling prints or placing flat impressions onto a glass platen above a camera unit. The process of obtaining prints by placing a tenprint card (prints taken using ink) onto a flatbed or high-speed scanner is called CardScan (or occasionally DeadScan). • The most common method of acquiring fingerprint images remains the inexpensive ink pad and paper form. Scanning forms ("fingerprint cards") with a forensic AFIS complies with standards established by the FBI and NIST.

44. AFIS • To match a print, a fingerprint technician scans in the print in question, and computer algorithms are utilized to mark all minutia points, cores, and deltas detected on the print. In some systems, the technician is allowed to perform a review of the points that the software has detected. • IAFIS maintains the largest biometric database in the world, containing the fingerprints and potential corresponding criminal history information for more than 47 million subjects.

45. COMPARE AND CONTRAST LATENT, PLASTIC AND VISIBLE FINGERPRINTS • Latent prints are fingerprints formed by oil and sweat secretions deposited by a person’s finger when they touch a surface or object. Latent prints are invisible and must be developed by chemical or physical means.

46. Plastic prints are impressions of a fingerprint left in a soft substance such as, wax, soap, putty, gum, stamps, candy bar, or fresh paint. They are also known as indented or molded prints and are not commonly found at a crime scene. COMPARE AND CONTRAST LATENT, PLASTIC AND VISIBLE FINGERPRINTS • Plastic prints are impressions of a fingerprint left in a soft substance such as, wax, soap, putty, gum, stamps, candy bar, or fresh paint. They are also known as indented or molded prints and are not commonly found at a crime scene.

47. COMPARE AND CONTRAST LATENT, PLASTIC AND VISIBLE FINGERPRINTS • Visible prints are fingerprints that have touched colored materials such as; blood, paint, ink, grease, chalk, mud or dust. Visible prints are not common at a crime scene.

48. Laboratory Exercise: Plastic Prints • Complete the plastic print lab • Complete the visible print lab

49. Option: Textbook: Forensic Science • Discussion: pg 50, first paragraph • Lab activity pg 51 • Pg 53, classify your prints • Statistics of prints, pg 55 • Pg 56, individualization of prints

50. Developing Prints: Lab work • To make latent fingerprints visible they must be developed or treated to make them visible. Once there is a visible print to work with, the next step is to recover it and document its location at the scene. • There are several physical and chemical methods of visualizing latent fingerprints. dusting, staining and chemical fuming are common methods.