Crime Busters

Implicate

point to guilt

Exonerate

point to innocence

Visible Prints

a print made by blood or a powder

Molded Prints

a impression in soap putty or wax

Latent Prints

a transfer of sweat oils onto a surface

Blob

a splatter that was made by fluid going straight down

Tail

points in direction of travel

Angle of impact

the angle of the tail showing where the fluid came from

Speed of impact

how fast the fluids going when it hits the surface

Passive spatters

a drip that falls straight down

Moving spatters

a spatter that hits at a angle

Transfer marks

a mark from direct contact from a object to a surface

iodine reagent

Used to test for presence of starch, dark blue or black when positive for starch.

chromatography

a process used for separating mixtures by virtue of differences in absorbency

distilled water

Water that has been purified, traditionally by evaporation, which leaves behind any solids that might be dissolved in the water. When the evaporated water condenses it is free of dissolved solids and virtually "100%" water. Normal tap water has impurities that can sometimes affect an experiment or chemical process.

chemical

produced by or used in a reaction involving changes in atoms or molecules

anhydrous sodium acetate

powder, white,soluble, ph-9yellowsih/green hcl-none iodine-none (sweet odor)

yeast

any of various single-celled fungi that reproduce asexually by budding or division

vitamin c

a vitamin found in fresh fruits (especially citrus fruits) and vegefltables

calcium carbonate

a salt found in nature as chalk or calcite or aragonite or limestone

table salt

white crystalline form of especially sodium chloride used to season and preserve food

sugar

a white crystalline carbohydrate used as a sweetener and preservative

flour

fine powdery foodstuff obtained by grinding and sifting the meal of a cereal grain

calcium sulfate

a white salt (CaSO4)

cornstarch

starch prepared from the grains of corn

baking soda

a white soluble compound (NaHCO3) used in effervescent drinks and in baking powders and as an antacid

powdered gelatin

grain,tan/orange, not soluble,ph-7,hcl-none, iodine-none,

powdered alka-seltzer

powder,white, soluble/fizzes, ph-9, hcl-fizzy, iodine-fizzy, fizzes w/ everything

sand

a loose material consisting of grains of rock or coral

aluminium

a silvery ductile metallic element found primarily in bauxite

iron

home appliance consisting of a flat metal base that is heated and used to smooth cloth

zinc

a bluish-white lustrous metallic element

magnesium

a light silver-white ductile bivalent metallic element

copper

any of various small butterflies of the family Lycaenidae having copper colored wings

tin

airtight sealed metal container for food or drink or paint etc.

lemon juice

usually fresh-squeezed juice of lemons

rubbing alcohol

lotion consisting of a poisonous solution of isopropyl alcohol or denatured ethanol alcohol for external use

household ammonia

An aqueous, basic potentially dangerous (basic aqueous solutions quickly attack human tissues, so gloves and eye protection are recommended when using household ammonia) solution of NH3: works as a general cleaner...used in windex

water

a fluid necessary for the life of most animals and plants

vinegar

sour-tasting liquid produced usually by oxidation of the alcohol in wine or cider and used as a condiment or food preservative

hydrogen peroxide

a colorless, unstable, oily liquid

density

the amount per unit size

fiber

a slender and greatly elongated solid substance

plastic

generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or used for making e.g. coatings and adhesives

chromatograms

files with the sequence visually represented by peaks of each flourescent nucleotide

spatter

the act of splashing a (liquid) substance on a surface

element

an artifact that is one of the individual parts of which a composite entity is made up

Tented arch

No delta. An arch with a sharp corner at the top point, resembles a triangle.

Plain arch

No delta. An gentle slope up with a more rounded top point, like a small hill.

Ulnar Loop

A loop pointing towards the pinky

Radial Loop

A loop pointing towards the thumb.

Double loops

In the twinned loop pattern, the recurving ridges present two loop formations, separate and apart. There are two points of delta. The flows for the deltas originate from the same side of the pattern.

Lateral pocket loop

In the lateral pocket loop pattern, the recurving ridges present two loop formations, separate and apart. There are two points of delta. The flows for the deltas originate from the same side of the pattern.

Plain whorls

Most important to know: sometimes simply referred to as "whorl".

Central Pocket Whorl

The central pocket whorl pattern consists of one or more free recurving ridges and two points of delta.

Accidental whorls

The accidental pattern will contain two points of delta. Rarely tested.

Composite

The composite pattern is composed of two or more different patterns, separate and apart exclusive of the arch.

Deltas

Triangles made from ridges.

Arch pattern

The Arch pattern is made up of ridges lying one above the other in a general arching formation.

Loop pattern

In order to distinguish between ulnar and radial loops you must:

1) know from which hand the loop pattern comes from and;

2) place your hand palm side down over top of the impression and determine if the recurving ridges originate from the little finger side or the thumb side.

If the ridges flow in from the little finger side this would be an 'ulnar' loop. If the ridges flow in from the thumb side this would be a 'radial' loop.

Whorl pattern

Whorls have two deltas and look like a target.

Island

An Island is a line-type which stands alone.

Bifurcation

Bifurcations are splitting lines in the pattern.

Core

Is the approximate center of the finger pattern impression

Ellipse

An Ellipse is a circular or oval shaped line-type which is generally found in the center of Whorl patterns.

Classification of Fibers

1. In general, one can say that the smoother the fibers, the more likely they are to be man made.

2. Most of the fibers made from natural sources such as animal or vegetable fibers are shorter fibers that are twisted together in some fashion. This often has the loose ends sticking out that look like fuzz.

3. In a real life most clothing is made from a blend of natural and man-made fibers.

Dye Test

One of the oldest methods of identification of fibers is the dye test. There are specific dies that only some types of fabric will take up. In other cases the dyes will look different colors with different types of fibers.

Animal hair

Burn Test observations: (wool, silk, protein based)

1. shrivels away from flame and curls up,

2. burns slowly, self-extinguishes.

3. Smells like burning hair m

4. Very small ashes, dark in color, bead-like mass that breaks apart easily

5. Microscope observation: medulla is more than 1 half of the hair.

Silk

1. Another common animal fiber, was once quite popular, but has been replaced to a great extent by such synthetic fibers as Nylon, Orlon, and Dacron.

2. Will dissolve in bleach.

3. Under the microscope the silk fiber appears as a thin, long, smooth and shiny cylinder. The fiber is double strands. The fabric is lightweight but can keep its wearer warm

Burn Test: Rapidly burns with uneven flames, smells of burning hair, the ashes are very brittle.

Cat Hair

finer than human hair or dog hair.

Dog Hair

can be of two different kinds. The outer coat is generally very course and often straight. The undercoat is often fine and can be very curly.

Human hair

1. Round hair tends to be straighter than oblong hair.

Flat hair tends to be kinky.

2. Dark hair is thicker than blond hair and red hair is the finest.

3. But then hair that has been colored artificially can give false clues.

4.Hair is composed of two basic layers.

4a). The inner layer contains the pigment(s). Melanin is the most common pigment in hair.

4b) The amount of melanin determines the color of the hair.

4c) The more pigment, the darker the hair.

4d) Some hair is white. It generally has bubbles in the inner layer.

5. Microscope observation: medulla is less than three quarters of the hair.

Vegetable fibers

Burn Test Observations: (cotton and flax, Cellulose based)

1. Does not shrivel away from flame

2. Ignites immediately with contact to flame, burns really quickly and readily in flame.

3. Continues to burn, has an "afterglow" when removed from flame until fibre expended

4. Smells likes burning paper

5. Ashes are fluffy, small, white to grey-coloured

Cotton

1. most widely used plant fiber

2. The fabric that produces soft, absorbs water, and wrinkles easily. is a fabric that is light and cool.

3. The fibers (use a few strands of absorbent cotton) when examined under a microscope will look like a flattened, irregular, twisted ribbon with short fibers.

4. Will NOT dissolve in bleach.

Burn Test Observation: A steady orange flame, turns black. smells like burning leaves, ashes is very crumbly, falls apart easily.

Linen

The strongest vegetable fiber, made from the stalk of the flax plant, its two to three times stronger then cotton. The fiber is long, shiny, and smooth, has poor elasticity, gets softer with use, absorbs water, . and wrinkles easily. Under the microscope it looks like miniature bamboo. Gets softer with use and considered a cool fabric for warmer climate.

Is often used to make handkerchiefs, tablecloths, napkins, summer clothing and blouses.

Hemp

This is a plant fiber that is similar to flax (linen) and ramie(but not as fine), therefore it possesses similar properties. Excels in fiber length, strength, durability, absorbency, antimildew and antimicrobial properties. This fiber can be of different qualities, the highest coming from Cannabis Sativa, and lower qualities being Sisal and Manilla Hemp.

Hemp works best in fabrics when mixed with other fibers, although high quality Hemp fabric is produced and wearable, although easily wrinkled.

This fabric also withstands water better then any other textile product and are used to make carpet backing rope, twine and sacks.

Synthetic fibers

Burn Test Observations:

1. Won't light in flames but melts close to the flame.

2. spirals back to stick to the tweezers.

3. Smells of black smoke like burning plastic, slightly sweet.

4. No Ashes, the fibers curl back.

A wide variety of synthetic fibers all have trade

names such as Nylon, Orlon, Dacron, Vinyon, Aralac, Acrilan, Velon, Dynel, Banlon and Lycra. Like rayon, these fibres resemble silk, and under the microscope look like smooth, lustrous, regular shaped cylinders. Synthetic fibers are easily identified because of their uniform thickness (the thickness of natural fibers varies).

Rayon

Rayon is one of the first successful artificial man-made fibers, although it is not considered synthetic. It is made from cellulose (plant). When manufactured, the rayon fibers resemble silk. This fiber is just as versatile and comfortable as natural fibers, such as cotton.

Under the microscope, the rayon fiber looks like a smooth, lustrous, glass-like cylinder, easily stretchable, doesn't wrinkle, is soft and absorbent and easy to dye, but is not a good insulator. Rayon can be made into cloth that is hard to distinguish from silk, cotton, linen, or wool.

Burn Test: Burned with a steady, rapid orange flame, smells of burning leaves, but no ash present.

Acetate

ACETATE is a created from wood. Under the microscope there are grooves that run the length of the fibers. Acetate is soft, smooth, and will melt under a hot iron. It does not absorb water. The fabric is cool

Nylon

NYLON is derived from coal. The fibers under the microscope are smooth and clear rods. Nylon is shiny, tough, stretchable and melts under a hot iron. The fibers are nonabsorbent, quick drying, and doesn't wrinkle. the fabric is cool but clammy.

Acrylic

ACRYLIC is made from petroleum. Under the microscope the fiber is dog-bone shaped with apparent cut ends. The fabric is lightweight, warm, and quick drying.

Polyester

POLYESTER is derived from petroleum. Under the microscope the rod shaped fiber looks like nylon but is not clear. The fiber does not wrinkle, is silk-like, strong, and absorbent.

Spandex

Spandex will expand to 54 times its original size

Glass Fiber

1. Glass fibers are made by stretching melted glass into fine filaments, which are spun into thread for weaving into cloth.

2. Lightweight glass fibers are used to make long lasting windows curtains, drapes, and lamp shades. 3. Heavier glass fabrics are used to make fireproof theater and school curtains.

Solid-Yeast

Tan pellets, not soluble, ph=7, no HCl or Iodine reaction, smells like fresh bread

Solid-Calcium Carbonate (powdered limestone, CaCO3)

White powder, non-soluble., ph=7, HCl fizz, Iodined color looks like mustard/peanut-butter, powder is very airy and hole-y

Solid-Cornstarch

White powder, non-soluble,ph=7, no HCl reaction, blackens in Iodine, pure white, feels slippery

Solid-Flour

White Powder, non-soluble,lumpy in water, ph=7, no HCl reaction, blackens in Iodine, clumps in water

Solid-Alka Seltzer (powdered)

White powder, soluble, ph=9, fizz with everything.

Solid-Baking Soda

White powder, soluble, ph=9, fizzy for long time in HCl, no Iodine reaction,kinda rough texture

Solid-Sodium Acetate

White powder, soluble, pH=9, no HCl or Iodine reaction, sweet odor and is endothermic

Solid-Sand

Random shape, white color ,non-soluble, pH=7, no HCI reaction, bad odor with Iodine, may have black specs

Solid-Vitamin C (ascorbic acid)

White sand, soluble,ph=2, no HCl, clears Iodine, can be tinted green, pink, orange. Distinctive smell

Solid-Gelatin

Grains in tan color, non-soluble., turns into gel, ph=7, no HCl or Iodine reaction, gels in water

Solid-Sugar (crystalline carbohydrate)

White grains, soluble,ph=7, no HCl or Iodine reaction, grains are slightly more rounded than salt

Solid-Salt (table salt - NaCl)

White grains, soluble., ph=7, no HCl, delayed reaction with Iodine

Liquid-Lemon Juice

Yellow(ish), Smells like lemons, pH 2.3

Liquid-Water

Clear, No smell, pH 7 Does nothing

Liquid-Hydrogen Peroxide

Clear, No smell, pH 7, Creates bubbles when shaken

Liquid-Ammonia

Clear, Smells awful, pH 11.6, pH can be detected by holding detector over it