solution
What are fingerprints?
An imprint/impression of the friction ridge of all or any part of the finger
What is a friction ridge?
The skin that covers the underside of the fingers, hands, toes and soles of the feet
What do friction ridges consist of?
Raised ares called ridges and the recesses between called furrows
What is friction ridge skin specialized for?
Traction
How does a person's patterns in their friction ridge skin change over time?
It does not change
What is the SWG for fingerprints?
Friction Ridge Analysis, Study and Technology (FAST)
What are the constituents of a typical fingerprint?
Approximately 98% water and 2% oils, dirt, grease and amino acids
What are the three types of fingerprint impressions
Patent, Plastic and Latent
What type of fingerprint impressions are visible without development?
Patent
What type of fingerprint impressions are left in a soft pliable surface like clay or wax?
Plastic
What type of fingerprint is not readily visible and is a transferred impression of friction
ridge detail?
Latent
What is the order of documenting and processing fingerprints?
Visual search, Photography (document location), Comparison quality photos,
Processing
What factors should you consider before processing for fingerprints?
What areas should be searched?
What are the surface characteristics?
Is the surface wet or dry?
What are the constituents of the fingerprints being processed?
Should the item be processed at the scene or collected and processed in the lab?
How should an item be packaged if collecting and processing in the lab?
Little physical contact with the packaging itself upon transport
What are techniques for processing fingerprints should a crime scene tech be familiar
with?
Powdering
Cyanoacrylate fuming
Recovery of fingerprints on porous surfaces
Recovery of fingerprints on non porous surfaces
Small particle reagent
Various chemical enhancement techniques
, How do you achieve the best results when powdering?
Choose the right brush
Use the appropriate amount of pressure when dusting
Choose the appropriate powder
Be careful not to over powder
Be careful not to over brush
What are the different types of brushes for powdering?
Fiber glass brush
Camel hair brush
Marabou feather brush
Magnetic wand
Which brush is typically used when searching for fingerprints?
Fiber glass
What brush is used in tight spaces and as a clean up brush?
Camel hair
Which brush is typically used when searching large areas of fingerprints and with
fluorescent powders?
Marabou feather
What brush is not actually a brush?
Magnetic wand
How do you choose the right powder?
Choose the powder that will contrast the most between the fingerprint and the surface
What are 4 examples of powders?
Black
White
Fluorescent
Magnetic
What powder is best of plastic surfaces to give contrast between a label and UPC
symbol?
Green and Red fluorescent with ALS
What is magnetic powder typically used?
Non-ferrous items
Fresh fingerprints
What is the best method for applying fingerprint powder?
Don't dip brush directly into powder jar
Transfer a small amount of powder to a paper fold
With powdered brush, lightly stroke the desired area in a circular motion
Remove excess powder
Enhance with a fine bristle brush
Why should you not dip the brush directly into the powder jar?
Could damage the brush
Usually leaves too much powder on the brush
Can contaminate stock
What may destroy the fine detail in the fingerprint?
Over powdering and over brushing
Applying too much pressure