Types of Hair
Characteristics:
Very Fine
Distinguishable by coronal scales on cuticle "strawberries on a stick"
Bat Hair
Skin turns a greyish-white color
Eyes become dull and film over white the pupils dilate
skin loses elasticity
Rigor, Livor, and Algor Mortis
Effects on a corpse after death
a point on a fingerprint in which a single ridge divides into two
bifurication
Animal Fibers shrivel, but don't melt (also animal fibers are the only things that dissolve in bleach)
Synthetic fibers melt and shrivel, and loose ends fuse together (usually smoother and uniform)
Vegetable fibers do not melt nor shrivel, but they ignite easily and usually appear charred after being burned
Burn Test
Type: Vegetable
Facts: Most widely used plant fiber and is fairly short
Burn Test Result: burns with a steady flame, smells like burning paper, able to blow flame from thread like a match, leaves a charred whitish ash
Microscopic shape: Irregular twisted ribbon
Cotton
Shaft Diameter: Fine to moderate with considerable variation
Cross Section: Flattened
Pigment granules: clomped
Hair Follicles of an African
Blood settles by gravity causing discoloration in the skin
Livor Mortis
Preferable when dusting off surfaces in residential and commercial settings also on apprehended vehicles, painted surfaces, and glass. Best used with a fiberglass brush and light dapples.
Regular Powder
These will be covered in compeititon
Paper chromatography
TLC Chromatography (Thin layer chromatography: glass slide with a silicone layer)
Ink chromatography
Juice chromatography (sample must be applied to the paper/TLC slide by another instrument)
Types of Chromatography
These will be covered in competition
Animal, vegetable, and synthetic/man-made
Types of Fibers
Shaft Diameter: Moderate wtih little variation
Cross Section: Round
Pigment Granules: Large patchy areas
Hair of an Asian
Lactic acid is produced in muscles causing stiffness which starts to develop one to four hours after death (expedites when electric shocked and is complete after 36 to 48 hours.
Rigor Mortis
Best applied to shiny and smooth surfaces using brushing strokes and can be seen using a magnetic applicator (has a magnet)
Magnetic Powder
The separation of mixtures into their constituents
Chromatography
Type: Animal
Facts: Most commonly used animal fiber
Burn Test Result: Shrivels, leaves brown-black residue, smells like burning hair
Microscopic shape: cylinder with scales
Wool
Shaft Diameter: Moderate with little variation
Cross Section: Oval
Pigment Granules evenly distributed
Hair Follicle of a Caucasian
Appear first on the body within minutes or hours of the death.
Blow Flies
an often elliptically-shaped, bowl like furrow surrounded by ridges
Enclosure
Powder applied to prints which stick to fatty acids and lipids.
(Can be Magnetic or Regular Powder)
Dusting
Type: Animal
Facts: Smoother than wool
Burn Test Result: shrivels leaves black residue, smells like burning hair
Microscopic shape: thin, long, and smoother cylinder
Silk
Shaft Diameter: Fine to moderate with considerable variation
Cross Section: Flattened
Pigment granules: clomped
Hair Follicles of an African
Arrive at the same time as blow flies, but generally arrive slightly later.
Flesh Flies
Formation in which a ridge is shaped like a dot
Island
CaCO3 + 2HCl ---> CaCl2 + CO2 + H2O
(Important)
Balanced chemical reaction made between calcium carbonate and Hydrochloric Acid
Type: Synthetic
Facts: Fibers can be any length
Burn Test Result: melts, only ignites when in the flame, drips when it burns and bonds quickly to any surface it drips on, produces sweet odor and hard, colored (same as fiber) ash
Microscopic shape: Completely smooth cylinder
Polyester