1. Fingerprints & Footprints
Chapter 11
Fingerprints
& Footprints

2. Chapter 11 HWC
What portion of the population has fingerprints with loop patterns?
Name the THREE types of fingerprints one might find at a crime scene.
Name the TWO most common methods of observing latent prints.
Name ONE of the other, less common methods of observing latent prints.
How might the fingerprints of a badly decomposed body be taken?

3. What portion of the population has fingerprint patterns that form loops? What fingerprint pattern makes up the rest of the population and how is it further divided?
2/3 of population have loops.
Other 1/3 have whorls, which also includes arches.

4. 2. How do computers assist in crime solving via fingerprinting?
Computers can scan and store digital fingerprint information.
Automated Fingerprint Identification Systems (A.F.I.S) can search hundreds of thousands of prints and match in seconds.
Can enhance poor quality of smudged prints
Internet allows data bases from around the world to be shared.

5. 3. Name and describe the THREE main types of fingerprints found at a crime scene.
Visible  made by fingers that have been in contact with a marker such as paint, ink, or blood.
Plastic  made by fingers pressing into material like soap, wax, or putty.
Latent  made when natural oil and perspiration present on the fingertips
are transferred to a surface.

6. 4. What are the two most common methods of observing latent fingerprints? How do these methods work?
Dusting  used on had and non-absorbent surfaces. Use special fingerprint powder, which sticks to the residues. Different coloured powders are used on varying surface colours.
Iodine Fuming  used on soft or porous materials. A fume hood is used, iodine crystals are heated. The vapours combine with residues and reveal the print.

7. 5. In point form, describe these methods of revealing fingerprints:
Ninhydrin Spray  forms a purple-blue colour when combined with traces of amino acids found in perspiration.
Silver Nitrate  reacts with the salt
in perspiration, which can be seen
under ultra-violet light.
Super Glue  works the same way
as iodine fuming.

8. Laser Lights  illuminate latent prints which causes chemicals in human perspiration to fluoresce. Chemicals can be used to enhance the effect. Prints then need to be photographed or lifted.

9. 6. At what point are the fingerprints of a dead body taken
6. At what point are the fingerprints of a dead body taken? Explain the problems that might occur when taking fingerprints of a dead body and how these problems are resolved:
Fingerprints taken once rigor mortis has passed
Badly decomposed bodies  hands or individual fingers are removed to help take prints.
Mummified bodies  fingertips softened by being soaked in glycol, lactic acid and water.
Drowning victims  glycerine or liquid wax injected into fingers. In extreme cases, the skin will actually be peeled away and mounted to surgical gloves.

10. 7. Besides fingerprinting, name TWO other identifying prints.
Palms
Soles of feet  often used to print babies.
Shoe print