fingerprints Flashcards
What does SWGFAST stand for?
scientific working group on friction ridge analysis, study and technology
what is the present day name for SWGFAST and what does it stand for?
OSAC: organization of scientific area committees
what are palmar ridges?
bottom of hands
what are plantar ridges?
bottom of feet
When does a fingerprint form?
6 month fetus (6 months pregnant)
what two people have the maximum genetic similarity/fingerprint similarity?
twins
how many sq. meters does skin cover?
1.5 to 2
how thick is skin?
2mm on palms, 4mm on heels, 0.5 on eyelids
what is the function of skin:
- container for skeleton
- sensory input
- elimination of waste
- gripping objects
what does sweat contain?
salts, amino acids, ammonia, and urea
what are the layers of skin
epidermis, and dermis
where are new skin cells formed?
adjacent to the dermis
what is the epidermis?
- outer layer of skin
- protective barrier
- constantly replacing cells
- consists of 5 layers
what is the dermis?
- inner layer of skin
- thick, fibrous and elastic giving skin flexibility and strength
- contains nerves, sweat glands, and blood vessels
- layer of connective tissue to support epidermis
- part of sensory reception and temperature regulation process
what components are in fingerprint secretions?
99% water
organic and inorganic salts
amino acids
fats
what are the three levels of fingerprint detail?
- pattern,
- ridge characteristics, and
- pores, ridge endings
what are the three categories in level 1 details?
loop, whorl, and arch
how many ridge characteristics does one finger contain?
150
what is level 3 details?
position of pores, edge shapes, creases, scars, and incipient ridges
can level 3 details be used to identify a fingerprint?
not on their own
what are incipient ridges?
immature friction ridge, thinner than those around it. not fully formed and may appear shorter and thinner in appearance.
What are the types of incipient ridges?
false, rudimentary, or nascent
what does ACE-V mean?
Analysis, comparison, evaluation, and verification
what happens during the Analysis step?
pattern and ridge characteristics of unknown impression are observed and noted
what would be included in notes about fingerprints?
substrate, matrix, deposition pressure, development medium, anatomical aspects, and clarity
what happens in the Comparison step?
observation of two or more impressions to determine the existence of discrepancies, dissimilarities, or similarities
what happens during the evaluation step?
assesses the value of the details observed during the analysis and comparison and reaches a conclusion.
is the evaluation step subjective or objective?
subjective in nature
what are the outcomes of evaluation?
- identification/individualization
- exclusion
- inconclusive
how do you label a finger print?
- circle with wax pencil or dry erase,
- use letter R or L with subsequent numbers,
- an arrow if direction helps
- date and initials
- scale close to the edge
- powder scale and circle
How can you check if the packaging procedure you are using is correct?
refer to the CFS handbook