MIDTERM: Forensic Science

Mathieu Orfila

Founder of forensic toxicology, trail of Maria Lafarge

Alphonse Bertilon

“Father of criminal identification” - anthropometry

Francis Galton

First definitive study of fingerprinting, classification system

Hans Gross

Application of science to criminal law

Landsteiner and Lattes

ABO blood groups and application to CSI

Calvin Goddard

Examination of bullets

Albert Osborn

Question document exams

Edmund Locard

Locard’s Exchange Principle - links between things

Frances Lee

Created dioramas

Sarah Bisel

Analysis of skeletons

Walter McCrone

“Microscopist”

Dr. Death

Forensic pathologist

Different types of evidence

Physical, testimonial, direct, circumstantial, reconstruction, associative

Locard’s Principle

"Every contact leaves a trace”

Class

Properties of evidence that can be associated with a group, NEVE with a single source

Examples of class characteristics

Fibers, paint, glass, bodily fluids

Individual

Properties of evidence that can be attributed to a common source with a high degree of certainty

Examples of individual characteristics

Ridges in fingerprints, striation marks

Results of a comparison

Inclusive, exclusive, inconclusive

Overview

Widest view

Mid-view

Location of evidence in a room in relation to other evidence

Close-up

Detail of a piece of evidence (with scale)

Crime scene search methods

Zone/sector, spiral, strip, grid

Body fluid packaging

Manila envelopes/paper

Volatile (digital) evidence packaging

Paint cans

Weapons packaging

Brown paper bag

Drug residue packaging

Plastic bags, vials

Trace evidence packaging

Paper fold, paper bag

Inductive reasoning

Draws general conclusions from specific instances

Abductive reasoning

Proposes the best possible explanations for specific observations

Deductive reasoning

Draws a specific conclusion from general premises

Latent print

Must be developed to be visualized, “natural” fingerprints

Patent prints

visible - blood, paint, ink, dust

Plastic prints

Pressed into a malleable surface

Deposition factors of prints

Pre-transfer, transfer, post-transfer

Pre-transfer

Condition or health of donor skin

Transfer

Surface conditions, pressure

Post-transfer

Environmental factors

Ridge flow

Overall flow - arch, loop, whorl

Ridge path

Minutiae

Ridge shape

Pores, edge shapes, thickness, angles

AFIS

Automated Fingerprint Identification System

Caliber

Diameter of bullet being fired

Lands

The ridges of metal between grooves - deep marks

Grooves

Spiral cuts - shallow marks

Firing marks

Breech marks

Ejector marks

Extractor mark

Passive drop

Flow patterns

Created when larger drops of blood move with gravity

Drip trail

Follows movements, sequence of individual dots

Bloodstain classification

Passive, projected, transfer

Arterial spurting

When major artery is severed

Cast-off

Flung from object in motion

Impact stain

When object hits blood source

Gunshot

Expirated

Internal injury mixing with air from lungs being expelled from nose, mouth - fine mist

Wipe

Clean to dirty

Swipe

dirty to clean

BPA Methodology

Detailed documentation, classification of patterns, scene context analysis, peer review and validation

Paint layers (inner to outer)

Substrate - primer - color coat - clear coat

Coroner

Elected

Medical examiner

Physician, can conduct autopsy

Cause of death

Injury or disease that produces physiological derangement

Mechanism of death

Physiological derangement produced by cause of death

Manner of death (5)

Suicide, natural, accidental, homicide, undetermined

Postmortem Interval PMI

Immediate (rapid), Early (mortis), Late (decomp)

Rigor mortis

Stiffening of muscles

Livor mortis

Collection of blood vessels caused by gravitational pull

Algor mortis

Body cools 1.5F every hour

Human decomp (5)

Fresh, bloat, active, advance, skeletal

Fresh

Self digestion (mortis)

Bloat

Rapid growth of bacteria, build up pressure

Active/advance decay

Fluids released, collapse of body cavity

Skeletal stage

50% of bone exposed

Human vs. non-human

Greater tubercle (quadrupeds=above head, human=below head)

Male vs. female

DNA or pelvis

Ancestry

Nose

Age

Dental development

Stature

Relate to persons height (long bones)

Long bones

Femur, tibia, humerus, fibula