1. Fingerprints

2. Before Fingerprints

3. Will West

4. Now Wait a Minute
William West

5. The Tale of the Tape Will West William West Body Height 178.5 cm
Reach
187
188
Trunk Height
91.2
91.3
Width of Head
19.7
19.8
Length of Head
15.8
15.9
Length of Right Ear
14.8
Width of Right Ear
6.6
6.5
Length of Left Foot
28.2
27.5
Length of Left Middle Finger
12.3
12.2
Length of Left Little Finger
9.7
9.6

6. The Two Wests

7. Why Do We Have Fingerprints?
Dermal Papillae

8. Ridges

9. Fundamental Principles of Fingerprints
A fingerprint will remain unchanged during an individual’s lifetime.
A fingerprint is unique due to minutiae.
Fingerprints have general characteristics ridge patterns that permit them to be systematically classified.

10. Fingerprint Principles
According to criminal investigators, fingerprints follow 3 fundamental principles:
A fingerprint is an individual characteristic; no two people have been found with the exact same fingerprint pattern.
A fingerprint pattern will remain unchanged for the life of an individual; however, the print itself may change due to permanent scars and skin diseases.
Fingerprints have general characteristic ridge patterns that allow them to be systematically identified.

11. Fingerprint Classes
There are 3 specific classes for all fingerprints based
upon their visual pattern: arches, loops, and whorls.
Each group is divided into smaller groups as seen in the lists below.
Arch
Plain arch
Tented arch
Loop
Radial Loop
Ulnar loop
Whorl
Plain whorl
Central pocket whorl
Double loop whorl
Accidentical

12. 60% of people have loops, 35% have whorls,
Interesting Info
Fingerprint Factoid:
60% of people have loops, 35% have whorls,
and 5% have arches
Did you know?
Dactyloscopy is the study of fingerprint identification. Police investigators are experts in collecting “dactylograms”, otherwise known as fingerprints.

13. Arches
Arches are the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present.
Tented Arches
Similar to the plain arch,
but has a spike in the center.
Spike or “tent”
Plain Arch
Ridges enter on one side and
exit on the other side.

14. Loops
Loops must have one delta and one or more ridges that enter and leave on the same side. These patterns are named for their positions related to the radius and ulna bones.
Radial Loop (Right Thumb)
Loop opens toward the left or the radial bone.
Ulnar Loop (Right Thumb)
Loop opens toward right or the ulna bone.
Delta
NOTE: On the left hand, a loop that opens to the left would be an ulnar loop, while one that opens to the right would be a radial loop.

15. Whorls
Whorls have at least one ridge that makes (or tends to make) a complete circuit. They also have at least two deltas. If a print has more than two deltas, it is most likely an accidental.
Central Pocket Whorl
Plain Whorl
Draw a line between the two deltas in the plain and central pocket whorls. If some of the curved ridges touch the line, it is a plain whorl. If none of the center core touches the line, it is a central pocket whorl.

16. Whorls – Part 2 Double Loop Whorl
Double loop whorls are made up of any two loops combined into one print.
Delta
Accidental Whorl
Accidental whorls contain two or more patterns (not including the plain arch), or does not clearly fall under any of the other categories.

17. Comparison 1
Arrested

18. Comparison 2
Arrested

19. Comparison 3
Side-by-side Comparison

20. Comparison 4
Comparison of minutae points

21. Comparison 5
Labeled Points for Comparison

22. Print Comparison- minutiae

23. Why Do We Leave Latent Prints?
Latent fingerprints are those that are “hidden” and are not visible to the naked eye. These prints consist only of the natural secretions of human skin and require treatment to cause them to become visible.
Most secretions come from three glands:
Eccrine--largely water with both inorganic and organic contaminants (salts)
Apocrine--secrete cytoplasm and nuclear materials
Sebaceous --secrete fatty or greasy substances.

24. Developing Latent Prints
Developing a print requires chemicals that react with secretions that cause the print to stand out against its background. It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print.
Powders--adhere to both water and fatty deposits. Choose a color to contrast the background.
Iodine--fumes react with oils and fats to produce a temporary yellow brown reaction.

25. Iodine Fingerprint

26. Developing Latent Prints (cont)
Ninhydrin--reacts with amino acids to produce a purple reaction.
Cyanoacrylate--”super glue” fumes react with water and other fingerprint constituents to form a hard, white deposit.
In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. It was first used by the FBI in Since lasers can damage the retina of the eye, special precautions must be taken and a filter used.

27. Ninhydrin Fingerprint

28. Cyanoacrylate Fingerprints

29. Other Prints Ears--shape, length and width
Face--pictures being used in Florida to find criminals
Voice--electronic pulses measured on a spectrograph
Feet--size of foot and toes; lines of the feet
Shoes--can be compared and identified by type of shoe, brand, size and year of purchase

30. Other Prints
Palm--lines can be identified and may be used against suspects.

31. Other Prints
Foot Prints are taken at birth as a means of identification for infants.

32. Other Prints Lips--display one of five common patterns
Short vertical lines
Long vertical lines
Rectangular lines that may crisscross
Diamond
Branching

33. Other Prints
Teeth--bite marks are unique and can be used to identify suspects. These imprints were placed in gum and could be matched to crime scene evidence.

34. Other Prints
The blood vessel patterns may be unique to individuals. They are used for today various security purposes.

35. “FINGERED” Crazy Criminals
A New Jersey resident phoned police after finding her back door slightly ajar with a muddy palm print on the glass. When the officer questioned the woman, it was determined that she had been gardening. When he compared her hand with the lifted print, he had a match!!

36. 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

38. It’s time to make some prints!
Avoid Partial Prints
GOOD PRINT Get as much of the top part of your finger as possible!

39. 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.