forensics

Formula	Substance	Burn Test	PH	HCL	Benedict	Iodine	NaoH	Uses
*C₂H₃NaO₂*	Sodium Acetate	Orange flame	8-9	no	no	no	no	Salt/vinegar flavoring, photo developers
*Na₂CO₃*	Sodium Carbonate	Orange flame	11.6-12	fizzes	no	no	no	Detergents, glass manufacture, cookingꜛ
*(C6H10O5)n*	Cornstarch	N/A	7.0	no	no	Turns black	no	Cooking
*CaSO4*	Calcium Sulfate	Bright Orange flame	6.7	no	no	no	precipitate	Drywall, gypsum
*NaHCO₃*	Sodium Bicarbonate (Hydrogen Carbonate)	Orange flame	8.3	fizzes	no	no	no	Baking soda, antacid, toothpaste
*H₃BO₃*	Boric Acid	Bright green flame	4.8	no	no	no	no	Athlete's foot treatment
*NH₄Cl*	Ammonium Chloride	Light green flame	6	no	Turns dark blue	no	no	Fertilizers, cough meds, glue
*C₆H₁₂O₆*	Glucose	Orange flame	7.0	no	Turns red	no	no	Energy (Humans)
*LiCl*	Lithium Chloride	Red (pink) flame	6	no	no	no	yes	Colorant, antidepressants
*KCl*	Potassium Chloride	Light Purple	6	no	no	no	no	Fertilizer, lethal injection
*MgSO₄*	Magnesium Sulfate	N/A	6	no	no	no	White precipitate	Bath salts, heart attack meds
*CaCO₃*	Calcium Carbonate	N/A	7	fizzes	N/A	PB	precipitate	Alka-seltzer
*Ca(NO₃)₂*	Calcium Nitrate	Red flame	5-7	no	N/A	N/A	precipitate	Treat calcium deficiency
*C₁₂H₂₂O₁₁*	Sucrose	Orange flame	6	no	no	no	no	Energy (Humans)
*NaCl*	Sodium Chloride	Yellow flame	7	no	no	no	no	Cooking

Plastic	Formula	Water	10% NaCl	46% Isopropanal	Veg. Oil	Burn test	Common Uses
PETE	*(C₁₀H₈O₄)_n*	sinks	sinks	sinks	sinks	Melts, bubbles, burns slowly, black soot	Soft drink bottles
PP	*(C₃H₆)_n*	floats	floats	floats	floats	Burns slowly, drips flames	Hot drink cups, jars, yogurt
PS	*(C₈H₈)ₙ*	sinks	floats	sinks	sinks	Burns rapidly, large amounts	Lab equipment
PVC	*(C₂H₃Cl)_n*	sinks	sinks	sinks	sinks	Melts, extinguishes when flame removed	Pipes, blood bags
HDPE	*(C2H4)n*	floats	sinks	sinks	sinks	Burns rapidly, white smoke when extinguished	Liquid, bleach, pipes
LDPE	*(CH₂-CH₂)_n*	floats	floats	floats	sinks	Burns rapidly, white smoke when extinguished	Potato chip bags
PMMA	*(C₅O₂H₈)_n*	sinks	sinks	sinks	sinks	Light blue flame, does not extinguish	Plexiglass
PC	*C₁₆H₁₄O₃*	sinks	sinks	sinks	sinks	Orange flame with black soot	Eyeglass lenses

Fiber	Source	Burn test
Silk	Animal	Shrivels, self-extinguishing black residue, smells like burning hair, leaves black bead
Linen	Vegetable	Burns at a constant rate, no smoke, smells like burning grass, produces sparks
Nylon	Synthetic	Curls, melts, black residue, smells like celery
Polyester	synthetic	Melts, only ignites in flame, drips, sweet odor
Cotton	Vegetable	Steady burn, smells like burning paper, charred white ash
Wool	Animal	Shrivels, leaves black/brown residue, smells like burning hair, very little smoke
Spandex	synthetic	Melts quickly

Blood spatter:

Low velocity: >1mm, self-inflicted, large drop like	Angle of impact (O)=arcsin(W/L)
Medium velocity: (may be cast off) blunt force, has trail	Theta (O)=angle W=width L=length arcsin= sin-1
High velocity: <1mm, gunshot or harsh force wound	The tail of blood shows the direction of movement

Bullet striations: caused by a gun’s unique rifling in the barrel, Gauge: diameter of the barrel (shotgun) Caliber: Diameter of a bullet (rifle)

Entomology: 1st Blowflies, 2nd Flesh Flies, 3rd Beetles/Moths

Blowfly life cycle: maggots > 24 hours, eggs < 24 hours, 2-3 weeks to fully develop. (1)egg (2) first-stage larvae (3) second-stage larvae (4) third-stage larvae (5) pupae (6)adulthood

Hairs: (Human) imbricate, medulla not full (Squirrel) thick medulla, imbricate (Cow) coarse and thick, coronal (Bat) coronal scales, fine (Horse) imbricate,

Blood: (Types of blood) A,B,O (Luminol) uses glowing reaction to locate masses of blood, a white pale yellow solid, reacts w/ iron, emits a chemiluminescence (Uni. Donor) O-

DNA: (DNA fingerprinting) invented 1984, Alec Jefferys, comm. 1987 (PCR) Denaturation, Annealing, Extension x(2^y) x=original DNA y=rounds of PCR

Glass: radial fracture; come off of the glasses main break → (Types of glass) annealed; causes greater injury, shatters, tabletops → tempered; heat treated, phone screens 4-5x stronger → laminated; has two layers, safest, used for cars → concentric crack; perpendicular to radial cracks

Soils: (Sand) pH → 4.5-5.5 (Silt) pH → 4.5-5.5 (Clay) pH → 5.5-7.0

Fingerprints: (Dusting) powder and brush → lightly dust and lift fingerprint, used for non-porous surfaces (Fuming) may use super glue and fume in chamber than adhere powder to show the print visibly, might fume with iodine, Cyanoacrylate, metallic vapors

(Key features) lake; a hole, independent ridge; disconnected line, island; small dot, crossover; resembles an “X”, spur; a small detour from correct line (6 prints) simple arch; round → tented arch; pointed → ulnar loop and radial loop; ulnar points towards pinky, radial towards thumb → simple whorl; one whorl → double whorl; two whorls on one finger