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Science Olympiad
Forensics Event
Hints, Tips, Things to Prep
What’s New
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Each team member may bring notes
Bunsen burner
PS (polystyrene) limited to non-expanded
Fingerprints
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DNA
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8 NCIC classifications
development techniques
PCR (not cell division)
Blood type
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ABO
avian vs mammalian vs reptilian
Overview
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Story arc presents
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suspects
types of evidence
which exhibit goes w/ which suspect
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Table of Results
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in notes?
Suspects
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exhibit list
Evidence
Powder Poly
Crime Scene
P1
R1
Suspect 1
P2
R3
Suspect 2
P3
R4
Suspect 3
P4
R2
Fiber
Hair Gr 2
Gr 2
Prep the Team
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Divide the responsibilities
Trust each other
Person 1
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start the chromatogram
powder tests
Person 2
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prep the Table of Results
polymers
hair
fibers
Make the "Notes" page
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8½" x 11 "
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Table of Test Results
dichotomous keys
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allowed 2 sheets this year
hand written
there are 2 sides to a sheet of paper…
entomology
flowcharts for tests
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polymer density
Make the "Notes" page
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tables of expected results
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powders
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distinguishing characteristics
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which test yields which positive indication
hair
fibers
glass
formulas
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Rf
spatter
Prep
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Pack the "Kit"
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see list in Rules
ex: thermometer
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ex: test tubes… or any devise in which they
can perform tests
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non-mercury (safety clause)
does not specify analog or digital
plural
test tubes spot plates, well plates
have enough to run all tests w/o washing
waterproof box for dirty stuff
ex: paper towels
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plural
does not specify all the same type
pack plenty (include enough for cleanup)
Categories of Exemplars
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Any 2(R), 3(S), 4(N) of
Powders
 fingerprints
Polymers
 DNA
Fibers
 glass
Hair
 entomology
Chromatography  spatter
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seeds & pollen
tracks & soils
blood type
bullet striations
Prep - Powders
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Develop a Flowchart
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Practice the tests
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chart of results in "Notes"
count equipment needed for "Kit"
Soluble
No
Iodine Test
Pos
HCl Test
Pos
Calcium Carbonate
yellow
Flame Test
Yes
Cornstarch
Calcium Sulfate
no effect
No
Electrolytic
Magnesium Sulfate
Pos
Glucose
Benedict's
Neg
Sucrose
Yes
pH
mild acid
faint green
Flame Test
Ammonium
Chloride
blue/green
base
HCl Test
vinegar
smell
Boric Acid
Sodium Acetate
no smell
Yes
CO2 Test
<10
pH
>10
Sodium Hydrogen
Carbonate
Sodium Carbonate
Sodium Chloride
No
yellow/orange
Calcium Nitrate
red/orange
Flame Test
crimson
purple
Lithium Chloride
Potassium Chloride
Prep - Polymers
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Burn Test Results
Polymer
"Burn" Behavior
PETE
Bubbles; slow burn; soot; pungent
HDPE
Fast burn; clean; drips flames; white smoke
LDPE
Fast burn; clean; drips flames; white smoke
PS
Fast burn; lots of black soot
PP
Slow burn; some drips flame
PVC
PMMA
PC
Melts more than burns; self-extinguishing
Bright flame; no smoke
Slow burn / smolder; no smell; self-extinguishing
Prep - Polymers
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Density Dichotomous Key
Unknown Polymer
Water
floats
46%
Isopropyl Alcohol
sinks
sinks
floats
PS
sinks
Saturated
NaCl
sinks
PETE
PVC
floats
PC
Vegetable
Oil
sinks
floats
HDPE
10% NaCl
floats
PMMA
PP
LDPE
Prep - Fibers
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Microscopic Examination
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cotton – twisted flat ribbon
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wool – hair; imbricate scales
Prep - Fibers
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Microscopic Examination
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silk – double ribbon
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linen - bamboo
Prep - Fibers
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Microscopic Examination
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nylon - tri-lobe cross-section
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polyester - round cross-section; delustering pits
Fibers – Burn Tests
No
Burns
Asbestos
Yes
No
Yes
Self-Extinguishing
Chars
Melts
Chars
Melts
Burning Grass
Grey Ash
Linen
Vinegar Odor
Hard Black Ash
Acetate
Burning Hair
Soft Black Bead
Silk
Celery Odor
Hard Grey Bead
Nylon
Burning Paper
Grey Ash
Cotton
Burning Meat
Hard Black Ash
Rayon
Burning Hair
Dark Ash
Wool
Sweet Smell
Hard Black Bead
Polyester
Tumeric Odor
Soft Black Ash
Acrylic
Prep - Hair
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Human
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Medullary index < 1/3
even distribution of pigment
Hair Cross-Section
Human Hairs
Prep - Hair
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Animal
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Medullary index > 1/2
Dog
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continuous medulla
scales usually not visible
ovoid bodies
root is spade-like
Prep - Hair
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Animal
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Medullary index > 1/2
Cat
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uniserial medulla; very large
spinous scales
root looks frayed
Prep - Hair
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Other Stuff to Know
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cuticle scale patterns
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coronal (crown like)
imbricate (flat; think shingles)
spinous (petals; think asparagus tips)
medulla patterns (Nationals)
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trace
discontinuous
continuous
uniserial ladder
multiserial ladder
amorphous (bubbly)
Prep - Chromatography
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How to "run" a chromatogram
How to measure Rf
spot dist
Rf 
front dist
Prep - Chromatography
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Typical chromatograms
Prep – Mass Spectroscopy
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Consider affinity
area under curve  % concentration
Optional - Fingerprints
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arch
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tented
arch
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loop
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radial
ulnar
Optional - Fingerprints
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whorl
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central
pocket
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double
loop
accidental
Optional - Fingerprints
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Minutia
bifurcation
 trifurcation
 ridge
 island
 dot
 delta
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Optional - Fingerprints
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Detection
powder
 cyanoacrylate fuming
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iodine fuming
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fats, oils
porous surfaces
noxious, corrodes surfaces
silver nitrate
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amino acids, fatty acids, proteins
non-porous surfaces
salts
ninhydrin
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amino acids
kills living tissues
Optional – DNA Chromatogram
• PCR – DNA copy machine
Option - Glass
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Index of Refraction
Hot-Stage Microscope
Stress Lines
Order of fractures
Option - Entomology
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Time Lines
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Blow Fly
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larva
maggot
pupa
adult
Beetles
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usually arrive after blow flies
Option - Spatter
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Directionality
Angle of Impact
Droplet Size
width of stain
sin  
length of stain
Option – Seeds, pollen
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visual microscopic comparison
Option – Tracks
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visual comparisons
directionality
Option – Soils
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compare composition
microscopic examination
soil triangle
Option – Blood Type
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ABO blood type
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perform antigen tests
RBC, WBC, platlet
human vs avian vs reptilian
Option – Bullets
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comparison of striations
Science Olympiad
Forensics Event
Hints, Tips, Things to Prep