CSI Unit 2

IAFIS

Largest collection of fingerprints in the world.

Core

Found near the center of all loop and whorl patterns.

Arch

Lines start on one side of the print and continue to the other side.

Whorl

Circles that do not exit on either side of the print.

Loop

Lines start on one side of the print, move to center, and leave on same side they started on.

Delta

Triangle shape in all loop and whorl patterns.

Primary Henry Classification

Each finger gets a number and is counted based on presence of whorls.

Secondary Henry Classification

Frequency of each fingerprint pattern is used to calculate probability.

Visible prints

Prints that can be seen with the naked eye.

Latent prints

Invisible prints.

Plastic prints

Prints that leave an impression on soap or wax.

Morphology

Form and structure of hair.

Hair

Protein polymers, repeating units, natural or synthetic.

Cuticle

Tough, clear covering of hair shaft.

Imbricate

Broken glass.

Spinous

Bundled spines.

Coronal

Stacked crowns.

Cortex

Middle layer, gives strength and mass and color.

Keratin

Tough protein polymer made up of 20 amino acids.

Melanin

Gives the hair color.

Medulla

Spongy interior of hair.

Fragmentary

Less than half medulla

Interrupted

More than half.

Continuous

Medulla that is all there.

Stacked

Multiple scales, only in animals.

Human medulla

Fragmentary, interrupted, continuous.

Animal medulla

Continuous or stacked.

Medullary index

d_medulla/d_total.

MI for humans

<1/3.

MI for animals

>1/2.

Round

Hair shape typical to Asian or Native American.

Oval

Hair shape typical to European, Mexican, and Middle Eastern.

Crescent moon

Hair shape typical to African.

Association

Link between unknown sample and known sample.

Questioned

Sample of unknown origin.

Exemplar

Sample of known origin.

Metabolite

Product of a substance formed by chemical processes in the body.

False positive

Hair absorbs chemicals from surroundings.

Cheiloscopy

Study of lip prints.

Fibers

Made up of filaments.

Textiles

Fabrics woven in a distinctive pattern.

Filaments

Twisted together to make a thread or fiber.

Fabric

Woven fibers.

Synthetic fabric

Human-made with spinnerets.

Natural fabric

From plants or animals.

Cellulose

Plant-based fiber.

Protein

Animal-based fiber.

Mineral

Human-made with natural ingredients.

Yarn

multiple fibers

Warp

Lengthwise (tall) yarn.

Weft or woof

Crosswise yarn.

Blend

Warp and weft are not same types of fiber.

Plain

Weave pattern of 1-1.

Twill

Weave pattern of 1-2.

Satin

Weave pattern of 1-4.

Knitted

Complex weave.