Anatomy and Physiology Lecture Notes

Unit 8 – Forensic Sciences - Introduction

AN INTRODUCTION TO SCIENTIFIC AND INVESTIGATIVE TECHINQUES

Forensic Scientist

n Uses REASON to maximize JUSTICE

n Applies SCIENCE to LAW

n RECOGNIZE

n IDENTIFY

n EVALUATE

n INDIVIDUALIZE physical evidence

n Independent Finders of FACT

n Testify to TRUTH

n Use tests that are

n RELIABLE

n ACCURATE

n REPRODUCIBLE

n UNBIASED

n Evidence cannot be influenced by theories

n DATA is basis of all conclusions

n ACCURATE DATA is derived from careful collection of evidence

n POOR EVIDENCE COLLECTION OR HANDLING can result in wrong conclusions

n Garbage in – garbage out

n DOCUMENTATION IS ESSENTIAL

Scientific Method

n What is EVIDENCE vs. COINCIDENCE

n Give WEIGHT (ranking) to results

n Attach a DEGREE OF CERTAINTY

n Break down theories to smallest component and test each

n Apply results to theories in order to PROVE or DISPROVE

n Components must ADD UP to THEORY

Organization of a Crime Laboratory

Ø Currently – 320 public crime labs operating under federal, state, county and municipal governments

Ø Four major FEDERAL crime laboratories:

FBI

DEA

ATF

Postal Service

Basic Services of a Crime Laboratory

Ø Physical Sciences: Drugs, glass, paint, explosives, soil, fibers, botanic materials, hairs, gunshot residues

Ø Biology: Bloodstains, semen, saliva

Ø Firearms: Examination of firearms, bullets, cartridge cases, shotgun shells, toolmarks

Ø Document Examination Unit: Questioned documents, inks, papers

Ø Photography Unit: Digital Imaging, Infrared, Ultraviolet

Ø Toxicology Unit: Body fluids and organs for drugs and poisons. Intoxilyzer unit

Ø Latent Fingerprint Unit: Processing for fingerprints

Ø Evidence Collection Unit - CSI

Ø Polygraph Unit

Other Forensic Science Services

n Forensic Pathology

n Investigation of sudden, unnatural, unexplained or violent deaths

n Autopsy performed to establish the cause of death

n Manner of death classified as natural, homicide, suicide, accident or undetermined

n Time of death determined by rigor mortis, livor mortis and algor mortis

n Forensic Anthropology

n Identification and examination of skeletal remains

n Bones can reveal species, sex, approximate age, race and skeletal injury

n Facial reconstruction can help identify “John or Jane Doe”

n Forensic Entomology

n Study of insects to estimate the time of death

n Insects lay eggs that hatch into larvae

n Stages of development tell how long ago the eggs were laid

n Temperature and other weather conditions affect the development

n Forensic Psychiatry

n Study of human behavior

n Determine if persons are competent to stand trial

n Develop a suspect’s behavioral profile based on previous patterns of other criminals

n Forensic Odontology

n Study of teeth characteristics, alignment and the overall structure of the mouth to identify a person

n Bite mark analysis compares marks on a victim to the teeth of the suspect

n Forensic Engineering

n Investigation of structural failures, accident reconstruction and causes of fires

n Attempts to determine if human intervention caused the structural failure

n Utilizes computer models and architectural models to help courts visualize crime scenes