Finger Printing

Ridges and pores activity
WOOD GLUE method

• Where are the pores found? Are they regularly spaced?
  • The pores are found between the ridges of the fingerprint and are quite regularly spaced throughout. The lines of the print are all quite regularly spaced, although at some parts, the lines merge or space out, hence forming different patterns.

Cyanoacrylate (Superglue) fuming method
Questions:
If the contrast of the white print against the black background is still too faint for a good detailed photograph to be captured, what could be done to enhance the fingerprint?
Powder dusting using a black substance such as lead could be used as the powder would get stuck between the ridges and pores of the print and allow it to be seen.

iodine fuming method
Questions:
What are the possible substances that may be used to render the prints more permanent?
Iodine can be mixed with solvents to create a liquid form of iodine and then sprayed onto the prints. This will allow the prints to last several hours.

For example,
1) Dissolve one gram of iodine in one liter of cyclohexane
2) Dissolve 5 grams of napthoflavone in 40 ml of methylene chloride (dichloramethane)
Why does the print disappear?
Iodine fumes evaporate very quickly.

Powder dusting method
Questions:
What is magnetic powder dusting and how does it work?
Magnetic powders dusting involves a fine magnetic powder being held by a magnetic applicator, which may then be gently moved across the fingerprint. The powder grains will get stuck in between the ridges of the fingerprint, enabling it to be seen. As no bristles touch the surface, this often damages the print less than other methods of developing the print.

Many other types of powders can be used, including chalk, charcoal and aluminium powder. The factors affecting which powder is used are adhesiveness, fineness, sensitivity, colour (so it can be seen on the surface) and flow.

Classification and identification of fingerprints
Introduction:
It is not clear which civilisation first utilised fingerprints as a form of identification. Evidence suggests that ancient Egyptians and Chinese create fingerprints on clay objects and official documents as a form of identification. There are however no known documents that describe how identification was conducted in ancient times.
Modern development of fingerprinting was mostly documented from 1858, when Sir William Herschel, British Adminstrator in District in India, required fingerprint and signatures on civil contracts. In 1892, Sir Francis Galton, a British Anthropologist and cousin to Charles Darwin, published the first book on fingerprints. He identified the individuality and uniqueness of fingerprints. In 1901, the first fingerprint bureau was eastablished in Scotland Yard. The system of classification was developed by Sir Edward Henry and is still the basis on which modern automated systems work to compare and identify fingerprints. 
The three basic fingerprint patterns are Whorl, Arch and Loop. There are more complex classification systems that further break down the pattern to plain arches or tented arches. Loops may be radial or ulnar. Whorls also have more detailed classifications.
According to the fingerprint database in the US:

• 60-65% are classified as loops
• 30 – 35% are classified as whorls
• 5% are classified as arches

Comparing 210 and America:

In 210's fingerprint database,

• 48% were classified as loops
• 45% were classified as whorls
• 3% were classified as arches