Digit deter/patterns Flashcards
What is a delta and how to recognize it?
An area on the friction ridges where three ridge systems meet.
It is usually located below and to the side of the pattern and has a triangular shape
Ridges from the delta tend to surround the centre of the pattern
Define the core
The approximate centre of the pattern
What are the SWGFAST pattern types ?
Arch - plain and tented
Loop- ulnar and radial
Whorl - plain, double loop, central pocket loop, accidental
What are the three main areas of the palm
Interdigital
Thenar
Hypothenar
What are the three main creases of the palm
Distal transverse crease
Proximal transverse crease
Thenar crease
What are the two interrelated aspects of digit determination
Patterns
Anatomical considerations
Other factors to consider when determining digit determination
Single digit found less than 50% of time
Even smeared prints adjacent can assist
Location of object
Height of fingers
How to recognize thumbs
Shape Core is lower in the fingerprint Often a side impression Found alone Position of fingerprint Tip ridges slip in ulnar direction Lack of phalange
The clockwise spiral of a whorl indicates what hand?
Left hand
The counter clockwise spiral of a whorl indicates what hand ?
Right hand
On a double whorl which loop will have an ulnar indication?
The ascending loop
What are some pattern considerations when trying to determine digits?
Flow or inclination is generally from ulnar bone
Predominant and more useful in clusters
Ridge paths may not be fully discernible but still useful
Lone digits can yield possible information based on ridge flow and their shape/size
What are some anatomical considerations?
How was the item held
Is it physically possible
The height
Do you just see edges
Is phalange impression evidence visible
Why are finger marks that are adjacent to a latent fingerprint valuable in digit determination?
The can help establish position of digits and a small amount of detail in adjacent impressions can help determine overall digit determination.
Which is the most commonly found pat in the Canadian fingerprint database?
Ulnar loop
