Trace Evidence. What do you think trace evidence is? Materials that are small enough to be easily overlooked by a crime scene investigator They are so.

Slides:

Advertisements

Similar presentations

Advertisements

Hair as Physical Evidence

Forensic Analysis of Hair

Trace Evidence: Hair Encountered at crime scenes Not good for “individualization” of physical evidence 1. No distinctive chemical properties 2. Although.

Unit # 4 - Hair1 Unit # 4 – Hair “For three days after death, hair and fingernails continue to grow, but phone calls taper off. - Johnny Carson Comedian.

TRACE ELEMENTS: HAIR AS EVIDENCE

{ Hair Analysis It’s Everywhere!!!.  Forensic hair examinations and comparisons are often used as important investigative and associative information.

Words to Know  Cuticle  Cortex  Medulla  Anagen phase  Catagen phase  Telogen phase  Follicular tag  Trichology  Melanin granules.

Aim:How is hair analyzed in forensics? Do Now:Explain the possible drawbacks of analysis of hair for drug metabolites. Homework:Pg. 230 #’s q 1-10.

Hair Growth  Human hair diameter ranges from µm  Coarse hairs grow slower & fall out less frequently than fine hairs  Head hair grows about.

Kendall/Hunt Publishing Company

Chapter 5: The Study of Hair “For three days after death, hair and fingernails continue to grow but phone calls taper off.” —Johnny Carson Comedian and.

Trace Evidence.

Forensic Analysis of Hair

Chapter 8 Hairs & Fibers.

Trace Evidence l: Hairs

NOVEMBER 13, 2012 STANDARD: SFS2b-Analyze the morphology and types of hair, fibers, soil and glass. EQ: What is the structure of hair fiber? Read the.

Hair 1. 2 Objectives You will understand that: Hair is class evidence. Hair can be used to back up circumstantial evidence. Hair absorbs and adsorbs substances.

Hair 1. 2 Objectives You will understand that: Hair is class evidence. Hair can be used to back up circumstantial evidence. Hair absorbs and adsorbs substances.

Chapter 5: Hair “For three days after death, hair and fingernails continue to grow but phone calls taper off.” —Johnny Carson Comedian and television host.

Chapter 5 Introduction Human hair is one of the most frequently found pieces of evidence at the scene of a violent crime. It can provide a link between.

Hair 1 ‡Most of trace evidence investigation involves:  hair  Fibers  Glass  Paint  Soil  Plant material Trace Evidence.

Topic: How is hair studied by a forensic scientist? Do Now:How often do you get your hair cut? How do people change the appearance of their hair? HW: Textbook.

Honors Forensic Science Wed., 1/29/14

The Study of Hair. Objectives The student will be able to: Identify the various parts of a hair. Describe variations in the structure of the medulla,

8.2 Notes – Hair continued. Objectives List hair features that are useful for microscopic comparison of human hairs Explain proper collection of forensic.

Hairs Trace Evidence.

Hair and Fiber Analysis. Introduction Color Structure Morphology Used to be the most useful forensic characteristics DNA is now obtained from cells in.

8 th Grade Forensic Science Presentation developed by T. Trimpe 2006

Hair Hair grows from a hair follicle The parts of a hair include the bulb, root, and shaft The bulb is an expansion at the end of the hair from which.

Medulla pattern Medullary Index Width of hair Scale pattern

Hair Extra-Credit ‡Bring in some animal hair (pets) ‡About 20 hairs ‡No roadkill samples!

Chapter 5 forensics_human_hairs_identi.htm Kendall/Hunt.

Introduction Human hair is one of the most frequently found pieces of evidence at the scene of a violent crime. It can provide a link between the criminal.

HAIR “For three days after death, hair and fingernails continue to grow but phone calls taper off.” —Johnny Carson Comedian and television host.

Chapter 5: Hair “For three days after death, hair and fingernails continue to grow but phone calls taper off.” —Johnny Carson Comedian and television host.

Chapter 5: The Study of Hair “For three days after death, hair and fingernails continue to grow but phone calls taper off.” —Johnny Carson Comedian and.

JS 113: Trace evidence- Hairs, Fiber and Paint I.Announcements, Assignments and Acknowledgements II.Learning Objectives (Chapter 8) a.Hair 1.Describe cuticle,

IDENTIFICATION AND COMPARISON OF HAIR Hair Note No.2.

Hair 1. 2 Objectiveshttp:// Body You will understand that: Hair is class evidence. Hair.

NOVEMBER 13, 2012 STANDARD: SFS2b-Analyze the morphology and types of hair, fibers, soil and glass. EQ: What is the structure of hair fiber? Read the case.

Hair and Fiber Analysis

What happened to the “Central Park Jogger”?

Hairs Trace Evidence.

Hair Forensics.

Hairs & Fibers Forensic Science

Chapter 5 Hair Kendall/Hunt.

Purpose for Hair Analysis

Trace Evidence 1: Hairs & Fibers

Trace Evidence l: Hairs and Fibers

Chapter 5 Chapter 5: Hair “ Kendall/Hunt.

NOVEMBER 13, 2012 STANDARD: SFS2b-Analyze the morphology and types of hair, fibers, soil and glass. EQ: What is the structure of hair fiber? Read the.

Hair Evidence Forensic Science 1.

Analyzing Hairs Forensic Science.

Forensic Hair Analysis

“For three days after death, hair and fingernails continue to grow but

“Hair today, gone tomorrow” -The Bald Man

Bell Question What does Locard’s Principle tell us and how is that important to Forensics Science? Answer on socrative.com Room Number:

Hairs Trace Evidence.

Trace Evidence.

Chapter 5 Hair Kendall/Hunt.

The Forensic Analysis of Hair

Analyzing Hairs Forensic Science.

Trace Evidence.

Hair Structure Linch CA et al JFS 46: 844

Presentation transcript:

Trace Evidence

What do you think trace evidence is? Materials that are small enough to be easily overlooked by a crime scene investigator They are so small they can be transferred (exchanged) by contact or in the air by air currents!

Locard’s exchange Principle? When 2 objects come in contact with each other, a cross-transfer of materials occurs When 2 objects come in contact with each other, a cross-transfer of materials occurs

Types of Trace evidence Hair Hair Fibers & threads Fibers & threads Metals Metals Paint & other building materials Paint & other building materials Soil, rocks, minerals, & debris Soil, rocks, minerals, & debris String, rope, & containers String, rope, & containers Wood & plant material Wood & plant material

Anatomy of Hair Root (internal end) Root (internal end) Medulla Medulla – Inner core – May or may not be present Cortex – main shaft surrounding the medulla Cortex – main shaft surrounding the medulla Cuticle – scaly outer covering Cuticle – scaly outer covering Tip (external end) Tip (external end)

Medulla Patterns 1.Continuous – a solid line 2.Interrupted – broken at regular intervals, like the dotted yellow lines on a road 3.Fragmented – broken, but not in a regular pattern 4.Absent

Anatomy of Hair

Human, cat, Dog, and Mouse Hair

What can hair tell us? We know it can tell us whether the hair is human or not. We know it can tell us whether the hair is human or not. If human: If human: – Race – Pulled out or fell out? – Part of the body it came from – How it was cut or dressed If animal, what species? If animal, what species?

Phases of Hair Growth

Location of Origin Scalp hair Scalp hair – Little diameter variation – More uniform distribution of pigment – No medulla or fragmented Pubic hair Pubic hair – Short and curly – Wide variations in diameter – Continuous medulla Beard hair Beard hair

Collecting the Evidence About samples from the scalp About samples from the scalp About 24 full-length pubic hairs About 24 full-length pubic hairs Need entire hair: Need entire hair: – Variations in color and other features alng length of hair Collected how??? Collected how???

Hair Analysis at Work Ennis Cosby Ennis Cosby Central Park Jogger Central Park Jogger – Microscopic analysis vs. DNA analysis

Hair Needed! Bring in samples of pet hair! Bring in samples of pet hair! Try to find hairs that have fallen out. (Where should you look?) Try to find hairs that have fallen out. (Where should you look?) Beard hair anyone? Beard hair anyone?