1. Fingerprints

2. Fingerprints – marks left behind when someone touches an object with their fingers.
Impression left in something soft – soap, wet paint, clay
Print left by a hand covered in dirt, blood or paint
Invisible deposit left by oil and perspiration secreted from the skin’s pores – “latent”

3. Everyone is unique
Fingers, thumbs, toes, lips, palms, soles of feet are all unique
Even identical twins are unique
Formed around 12th week of pregnancy
Will never change – even if injured – will grow back as skin heals
As body grows, fingerprints grow

4. Three main patterns
Arches
Loops
Whorls

5. Can be divided into smaller groups:
Arch: plain arch, tented arch Loop: radial loop, ulnar loop Whorl: plain whorl, central pocket whorl, double loop whorl, accidental whorl

6. Trends in Certain Populations
In Western European populations, the loop accounts for about 60% of all prints.
Whorls and composites make up about 35%
Arches found in about 5% of all prints
Loops most common among black Africans
Central Europeans – arches most common

7. Make a chart below the cards:
Staple or tape your fingerprint cards to the top of a piece of notebook paper, leaving space below each card to write some information.
Using your fingerprint cards, identify the patterns on all ten fingers. Record on your paper below the card piece of paper.
Make a chart below the cards:
Record the number of each pattern you have on your ten fingerprints.
Arches
Loops
Whorls

8. Class Data On board, record your data from the table
Create a bar graph showing the class data for each type of fingerprint.

9. Deltas

10. 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.

11. 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.

12. 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.

13. 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.

14. Fingerprint Minutiae
Look for these on your fingerprints. Compare with a partner.

15. In some jurisdictions there must be a certain number of characteristic points in common if two fingerprints are to be accepted as a match. In most jurisdictions, there is no minimum number of points of identity required.

16. When are fingerprints taken?
When a crime has been committed, all people known to have been at the scene need to be taken
Suspects are fingerprinted so they can be investigated further or eliminated from further inquiries – “elimination fingerprints”