Safety Crime Busters How to Be Successful at This Event Presented By Scott A Holdren Regional Director State Event Supervisor National Event Supervisor Students must wear Closed-toed shoes ANSI Z87 indirect vent chemical splash goggles gg Pants or skirts that cover the legs to the ankles Long sleeved shirt that reaches the wrists Chemical Apron or Lab Coat that reaches the knees What To Bring Test tubes & racks, spot plates, well plates, reaction plates or similar small containers for mixing Something for scooping Droppers Funnel &/or Filter Paper ph paper Conductivity tester (9V) Thermometer What To Bring Flame Test stuff Microscope slides and cover slips Magnifying glass Forceps or tweezers or tongs Writing instruments & Ruler Paper towels One 8½ x 11 two-sided page of notes containing information in any form from any source Divide the responsibilities; Trust each other Person 1 Powder tests Person 2 start the chromatogram Polymers Hair Fibers Transfer all identifications to the map Prep the Team Shared Topics Fingerprints DNA Glass Entomology Spatter Seeds / Pollen Tracks / Soils Blood Bullet Striations The Story Arc Read the back-story after identifying exhibits Suspects Description General tendencies Restrictions (allergies, location, alibi ) Evidence List of exhibits Map Which exhibit goes w/ which suspect
Find or develop a Flowchart chart of results on birch bark Powders Flowchart - Powders Flowchart - Polymers Polymer Float Chart Prep Fibers; Visual Cotton Twisted flat ribbon Wool Hair Transparent w/ rough edges Silk Transparent & very thin Linen / Flax Bamboo Nylon Synthetic Uniform diameter Any color Polyester Synthetic Uniform diameter Clear Delustering Pits Prep Fibers; Burn Tests Chars Burning Grass Grey Ash Linen Burning Paper Grey Ash Cotton No Burns Yes Self-Extinguishing No Asbestos Yes Melts Chars Melts Vinegar Odor Hard Black Ash Acetate Burning Meat Hard Black Ash Rayon Tumeric Odor Soft Black Ash Acrylic Burning Hair Soft Black Bead Silk Burning Hair Dark Ash Wool Celery Odor Hard Grey Bead Nylon Sweet Smell Hard Black Bead Polyester
MI < 1/3 Human MI > 1/2 Not Human Translucent, obvious medulla Dark, streaky, can t see medulla Dark, near-black medulla Horse Mixed hairs Uniform width Medulla: solid bubbly absent Prep - Hair Dog Mixed hairs Thick & dark Thin & transparent MI near ½ Dark, continuous medulla *** Ovoid bodies Cat Mixed hairs Dark and transparent Semi-uniform size Uniserial ladder Bat Distinctive spiral Prep - Hair Other Stuff to Know cuticle scale patterns coronal (crown like) imbricate (flat; think shingles) spinous (petals; think asparagus tips) medulla patterns trace discontinuous continuous uniserial ladder multiserial ladder Typical Chromatograms Chromatography Chromatography How to "run" a chromatogram How to measure R f R f = spot dist front dist Fingerprints Fingerprints arch whorl accidental tented arch No Deltas central pocket loop radial ulnar 1 Delta double loop
Minutea Bifurcation Ridges Islands deltas Development Techniques Dusting Iodine Fuming Ninhydrin Cyanacrylate Fuming Fingerprints DNA Chromatograms Electrophoresis process PCR Index of Refraction Hot-Stage Microscope Stress Lines Order of fractures Glass Time Lines Blow Fly larva maggot pupa adult Entomology Beetles usually arrive after blow flies Directionality Angle Impact Speed Spatter width of stain sinθ = length of stain Seeds & Pollen visual microscopic comparison 1&4 Rule
Visual Comparison Matching Directionality Weight Tracks Visual matching Color Grain size Elements in the soil Magnet (iron?) ph HCl (calcium varieties?) Soils ABO blood type perform antigen tests RBC, WBC, platlet Blood Bullet Striations human vs avian vs reptilian Disorganized Washing Common Pitfalls Suggestion Test tubes Spot Plates or Well Plates - wood splints for scooping Too much time discussing which test to perform Not answering the analysis questions
Mark up the Crime Scene Map Suggestion Crime Busters How to Be Successful at This Event Presented By Scott A Holdren SHoldren@rcscsd.org