18 DNA EvidenceShaft: mitochondrial DNA (mtDNA)Root: nuclear DNA
19 Growth Stages of the Hair: Anagen Stage: The active growth phase of the hair follicle. Catagen Stage: The transition period between growth and rest. Hair continues to grow, but at a decreasing rate. The root bulb looks elongated from being pushed out of the follicle.Telogen: The rest period for the follicle. The current hair is shed and no new growth takes place for a period of time.
22 Hair CollectionCollected from crime scene by plucking, shaking and scraping surfacesUse tape over small surfacesVacuum large surfacesInitial analysis performed under compound microscopeCollect 50 hairs from suspect for comparison. Not all hairs are the same
23 Testing For ChemicalsNeutron activation analysis (NAA) – identify 14 different elements in hairAntimony, argon, bromine, copper, gold, manganese, silver, sodium, zincHair grows about 1.3 cm per month – calculate timeline for exposure to toxins or poison