unit 3: types of prints (impressions as evidence) Flashcards
When do fingerprints form?
During the 10th week of gestation
Where does development of the prints happened?
In the basal layer of the skin where the new skin cells are produced
True or false is the fingerprint pattern permanent?
Yes the outer layer of the epidermis protects it
What are the three major ridge patterns?
Loops, arches, whorls
what percentage of the populations have loops arches and whorls?
65 of the population has loops, 30% has whorls, 5% have arches
What is a delta?
Ridges that run in different directions up and below it
What are the two types of arches?
plain arches and tented arches
What is the difference between a plain arch and a tented arch?
tented arches have a delta
What are the four different types of whorls?
plain whorl, Central pocket loop whorl, double loop whorl, accidental whorl
What’s the difference between a plain whorl and a central pocket loop whorl?
plain whorls look more circular a while central pocket loop whorls look more oval
What are the two loops?
Ulnar loop and radial loop
What is the difference between a radial loop an ulnar loop?
radial loop opens towards the thumb and ulnar loop opens towards the pinky
What is a minutiae?
Combination of small details in the shapes and positions of the ridges
Name the different types of minutiae:
Ridge ending, fork or bifurcation, island Ridge, dot, bridge, spur, eye, double bifurcation, Delta, trifurcation
How many individual ridge characteristics are on the average fingerprint?
150
Name the three types of impressions:
Patent prints, plastic prints, latent prints
1792 to 1750 BC
Archaeologists discovered fingerprints pressed into clay tablet contracts
300 BC
inked fingerprints on all official documents, such as contracts and loans
1684
Earliest record of the study of the patterns on human hands
1788
The arrangement of skin ridges is never duplicated in two persons
1823
Nine distinct fingerprint patterns including loops spirals circles and double whorls
1856
Fingerprints are unique to individuals and are not altered by age
1879
alphonse Bartillon created a way to identify criminals using physical measurements taken from prisoners
1888
Classification system for fingerprints
1896
Fingerprint records divided by arch, whorl, or loop patterns — each fingerprint card in the system was imprinted with all 10 fingerprints of a person and worked with individual characteristics
2012
Fingerprints are digitally taken in the FBI maintains IAFIS
What is a fingerprint?
An impression left on any surface that consists of patterns made by ridges on a finger
What are the fingerprints made up of?
They are made up of water, oils, and salt
How to collect latent fingerprints?
They can be lifted by being dusted using carbon-based powders, metal or magnetic powders, or a variety of chemicals
What is used to lift and preserve the fingerprint?
Tape
What is the ratio of false identification made by fingerprint examiners?
1 to 5
How do criminals avoid identification?
many use acid, burn themselves, cut themselves, use sandpaper, burn it off, or use lasers
True or false mutilation cause the fingerprints to disappear?
false
How to lift shoe and foot impressions?
Latent impressions can be made visible by using luminal dusting or using electrostatic dust. Plastic impressions can be lifted using plaster to make a cast
Databases contain the names of _______ and _______ used to identify different types of shoes.
Specific manufactures; tread patterns
examining feet tracks can reveal:
If a person was running or walking, if someone is injured, or the likelihood that someone is older or disabled
True or false larger shoe size means taller height
true
Every make and model of a vehicle has its own ______ and _____.
Track width; wheelbase measurements
What are skid marks?
Sudden braking; the distance the brakes are applied; the velocity
What are yaw marks?
Donuts, curves, melting tires, striped shape
What are tire scrubs?
Damaged or overloaded tires from impact, curved and irregular, determine area of impact
How to collect dental impressions:
Bite marks should be photographed ASAP, photographs should include a ruler to establish a reference for size, if possible swab the bite mark to obtain DNA evidence
