FIVS 215 FINAL (NEW MATERIAL)

Locard Exchange Principle

Objects or Surfaces Which Come Into Contact Always Exchange Trace Evidence

Paul Kirk

" ... more laboratory failures are due to inadequate collection of existing evidence than to the failure of the laboratory to examine evidence properly"

Passive documentation

- No real insight into the circumstances of the incident

- Investigator guessing at what might be important

Active documentation

- Uses the scientific method

- Allows investigators to focus on important evidence

Evidence must be collected in a fashion that what?

- Maintains the integrity of the evidence

- Is safe (for any and all that must encounter it)

Maintaining the integrity of the evidence

- The evidence must be sealed

- It must be packaged so as to preserve it

- It must be free of potential contamination.

Is safe (for any and all that must encounter it)

- Firearms should be unloaded.

- Sharp objects should be in special containers

- Appropriate cautions should be taken with explosives and toxic materials.

- Appropriate cautions should be taken with biohazards.

Which one is the cuticle?

A

Which one is the cortex?

B

Which one is the medulla?

C

Which side is proximal, D or E?

D

Which side is distal, D or E?

E

Which one is the ovoid body?

F

Which one is the cortical fusi?

G

Which one is the pigment granule?

H

Melanin granules are formed in the follicle by specialized cells called what?

Melanocytes

The medulla originates from matrix cells closest to the what?

Dermal papilla

The Anagen Phase (Growing)

(80-90% of the hair follicles)- the follicle is actively producing hair.

The Catagen Phase (Transition)

(2% of the hair follicles)- - the transition period from the anagen to the telogen phase. The melanocytes in the follicle contract and cease to produce and distribute pigment granules.

The Telogen Phase (Resting)

(10-18% of the hair follicles)- the follicle is mature, dormant or resting stage.

What is the hair growth rate?

1/2 Inch/Month

What is the racial characteristics of Negroid?

Diameter: 60-90 um

Cross section: flat

Pigmentation: dense and clumped

Cuticle: ------

Undulation: prevalent

What is the racial characteristics of Caucasoid?

Diameter: 70-100 um

Cross section: oval

Pigmentation: evenly distributed

Cuticle: medium

Undulation: uncommon

What is the racial characteristics of Mongoloid?

Diameter: 90-120 um

Cross section: round

Pigmentation: dense auburn

Cuticle: thick

Undulation: never

Somatic Origin: Scalp

head hair, 100-1000mm long, 25-125μm diameter; 0.4mm/day growth; small root; apered tip, little diameter variation; various medullation; often with cut tips; may be artificially treated

Somatic Origin: Pubic

pudendal; 10-60mm long; coarse diameter and prominent diameter variation and buckling; broad medulla; follicular tags common; asymmetrical cross section twisted and constricted; may be straight , curved or spirally tufted.

Somatic Origin: Vulvar

secondary pubic hair; finer and shorter than pubic hair, maybe abraided.

Somatic Origin: Chest

pectoral; moderate to considerable diameter variation; long fine arch-like tip; usuallylonger than pubic hair

Somatic Origin: Beard

facial hair, very coarse, 50-300 mm long; large root, irregular structure; often triangular cross-section; complex medullation; blunted or razor cut tip; grows 40mm/ day.

Somatic Origin: Axillary

arm pit; 10-50mm long, grows .30mm/day; coarse; blunt tip, abraided or frayed;usually straighter than pubic hair; many cortical fusi; sometimes yellowed and bleached.

Somatic Origin: Eyebrow

supercilary; 1cm long; .16 mm/day growth; curved; relatively coarse for length; smooth curve with punctate tip and large medulla.

Somatic Origin: Eyelash

cilary; less than 1cm long; short curved pointed hair.

Somatic Origin: Limb

leg and arm hair: 3-6 mm long, fine tips, irregularly medullated; often indistinctly and slightly pigmented

Somatic Origin: Ear

tragic, pinnae; downy

Somatic Origin: Buttocks

anal hair, short blunted and abraided hair

Somatic Origin: Nose

similar to facial hair

Which one is a double chevron?

C

Which one is a regular mosaic?

I

Which one is an irregular mosaic?

D

Which one is an irregular wave?

F

Which one is a diamond petal?

B

Which one is a irregular petal?

E

Which one is a pectinate?

H

Medullary Index

Medulla width/ hair width

Which one is fragmental?

A

Which one is uniserial ladder?

B

Which one is multiserial ladder?

C

Which one is Simple unbroken amorphous?

D

Which one is unbroken cellular?

E

Which one is unbroken vacuolated?

F

Which one is unbroken with cortical intrusions?

G

Which one is unbroken lattice?

H

Dyed Hair- Demarcation Line

See picture

Pigment Aggregates

See picture

Is it discontinuous, continuous, or translucent?

Discontinuous

Is it discontinuous, continuous, or translucent??

Translucent

Mitochondrial DNA

Follicular tag- richest source of nuclear DNA. Therefore, anagen and beginning catagen hairs have a higher rate of success for DNA typing.

Control Samples

- Known samples; must be representative (25-100 hairs)

- Alternate known or "anticipated alibi" samples

- "Contamination" concerns

The 4 C's

Carat, Clarity, Color, Cut

Karat

1/24 Pure Gold

1 point equals what in diamonds?

0.01 ct

Specific Gravity

Dry weight/Loss of Weight in Water

Carat

0.2g, 100 points

Single cut has how many facets?

18

Tolkowsky is also known as a what cut?

American cut

Gemscope

Dark field stereoscope with Fluorescent Incident Light for Color Grading

Which is the acrosome?

C

Which one is the head?

A

Which one is the middle piece?

B

Which one is the Tail?

E

Which one is the mitochondrial sheath?

D

Which one is the girdle?

B

Which one is the pavilion?

C

Which one is the crown?

A

Which one is table?

D

Which one is bezel?

E

Which one is star?

F

Which one is the upper girdle?

G

Which one is the lower girdle?

H

Which one is the pavilion main?

I

Which one is the culet?

J

Which one is the rachis?

A

Which one is the calamus?

B

Which one is the quill?

C

Which one is the quill point?

D

Which one is the down?

I

Which one is the feather fiber?

J

Which one is the barbs?

E

Which one is the barbules?

F

Which one is the nodes?

G

Which one is the specialized nodes?

H

Gymnosperms

exposed seeds

Conifers

needlelike or scalelike foliage, usually evergreen, excurrent form (dominant main stem or trunk with lateral side branches). Includes the largest living plants (sequoias), and the oldest plants (bristlecones pines).

Angiosperms

encapsulated seeds

Monocots

have one initial seed leaf. (grasses, corn, bamboo, palm and rattan)

Dicots

have two initial seed leaves (hardwoods)- dendritic (branching and rebranching) broad-leafed foliage, mainly deciduous (lose their foliage during winter dormacy)

What is the structural planes? What do they do?

Transverse plane (X) is perpendicular to the stem axis

The radial plane (R) passes through the pith

The tangential plane (T) forms a tangent to the cylindrical plane of the growth rings

Which one is longitudinal and which one is ray cells?

Longitudinal is B and Ray is B

Rays- 10% of cells elongated, flattened ribbons, perpendicular to the stem.

Vessel elements

largest cells in hardwoods, with thin walls and spacious cell cavities (sap conduction). They always occur end to end. Each end wall has an opening called a perforation. When cut transversely, the opening of a vessel on a cross- sectional surface is called a pore. Pore size and distribution is important for ID.

Simple perforation

oaks, ashes, maples and basswood.