SEPTEMBER 24, 2012WARM-UP:STANDARD: SFS1C DETERMINE THE PROPER TECHNIQUES TO SEARCH, ISOLATE, COLLECT AND RECORD PHYSICAL AND TRACE EVIDENCE.

EQ: What is the process by which physical evidence is collected?Write the following questions:1. What was the name of the missing teen?2. What were the circumstances surrounding her disappearance?3. Who is the lead suspect in this crime?

FORENSIC SCIENCE

PHYSICAL EVIDENCE AND THE CRIME SCENECHAPTER 2

PHYSICAL EVIDENCE

Any object that can establish that a crime has been committed or can link a crime and its victim or its perpetrator

Presence must be recognized at the crime scene.

SECURING AND ISOLATING THE CRIME SCENE

The first officer on the scene must obtain medical help for any injured parties and arrest the perpetrator, if possible.

The crime scene must be isolated and protected as much as possible.

Unauthorized personnel should be kept away from the crime scene.

The lead investigator must set the boundaries and determine the entry and exit pathways.

RECORD THE SCENE

The crime scene needs to be permanently recorded in the original state. Needed for future

reference Needed for court

3 methods 1. Photography 2. Sketches 3. Notes

1. PHOTOGRAPHY must be unaltered,

objects cannot be moved If something is

removed from the scene, it is noted but is not reintroduced.

scene photographed as completely as possible, including surrounding areas, from all angles

physical evidence photographed to show location and position, close-ups taken to show detail, ruler can be added to show scale

• Photographing the Crime Scene:

1. PHOTOGRAPHY (CONT.)

digital pictures can be altered, sometimes not acceptable in court, but can be joined to show 3D picture of scene

Videotaping can be used in same manner of digital camera, can also capture narration of scene

2. SKETCHES Rough sketch

contains actual dimensions of the scene, accurate measurements made with tape measure

shows location of objects deemed of value to scene

basic diagram of scene

compass added to show north

legend or list of items added

2. SKETCHES (CONT.) Finished sketch

Must contain information from rough sketch

More precise, neater

Can be made with computer

A cat’s urine glows under a blacklight?

Months that start with a Sunday will always have a Friday the 13th?

111,111,111 x 111,111,111 = 12,345,678,987,654,321?

3. NOTES Must include detailed

written description of the scene with the location of items of physical evidence recovered

Must also identify the time an item was discovered, by whom, how and by whom it was packaged and marked, and the disposition of the item after it was collected

3. NOTES (CONT.)

May be only source of information when preparing for court case years later, should be very detailed

Tape recordings and videotaping may be helpful at scene, used to make notes later

DEALING WITH

PHYSICAL EVIDENCE

• Uses and Information from Physical Evidence:

Physical Evidence

SuspectVictim

SceneObject

DEALING WITH PHYSICAL EVIDENCE After the lead detective does

the preliminary walk-through, a more thorough search for physical evidence begins.

Once found, evidence must be collected and stored in a way that preserves its integrity for forensic comparison and analysis.

The chain of custody has to be maintained at all times.

CONDUCT A SYSTEMATIC SEARCH FOR EVIDENCE

One person should supervise and coordinate the collection of evidence.

May divide the area into segments and collect evidence individually, or move from the outside in to the center.

Search area must include probable points of entry and exit used by the criminals.

What to search for will be determined by the nature of the crime.

Evidence collector ensures that evidence is collected, packaged, marked, sealed, and preserved in a consistent manner

How many people supervise and coordinate the collection of

evidence?

COLLECT PHYSICAL EVIDENCE Take all clothing worn by participants in a crime. Each

piece should be packaged carefully and separately.

ITEMS OBTAINED FROM THE BODY & SENT TO THE LAB: 1. Victim’s Clothing 2. Fingernail Scrapings 3. Head and pubic hairs 4. Blood 5. Vaginal, anal, oral swabs (sex-related crimes) 6. Recovered bullets from the body 7. Hand swabs from shooting victims (gunshot residue

analysis)

Critical areas of a crime should be vacuumed, and sweepings from different areas should be packaged separately.

Fingernail scrapings should be taken from individuals who may have been in contact with other involved individuals.

OCTOBER 16, 2012WARM-UP: STANDARD: SFS1c Determine the proper

techniques to search, isolate, collect and record physical and trace evidence.

EQ: Can you determine whether or not evidence was collected, labeled and sealed properly?

Write down each sentence and fill-in-the-blank. 1.The __________ ultimately decides the

significance of physical evidence in a trial. 2. If a crime takes place outside and it rains, shoe

prints will probably ___be/not be___ collected. 3. Blood soiled items should always be air-dried

and collected in a(n)_____________.

judge

paper bag

PACKAGING Forceps and similar

tools may have to be used to pick up small items.

Unbreakable plastic pill bottles with pressure lids are excellent containers for hairs, glass, fibers, and various other kinds of small or trace evidence.

Manila envelopes,screw-cap glass vials, or cardboard pillboxes are adequate containers for most trace evidence encountered at crime sites.

Ordinary mailing envelopes should not be used as evidence containers because powders and fine particles will leak out of their corners.

PACKAGING

Small amounts of trace evidence can also be conveniently packaged in a carefully folded paper, using what is known as a “druggist fold.”

If bloodstained materials are stored in airtight containers, moisture collecting inside cause the growth of mold, which can destroy the evidential value of blood.

In these instances, wrapping paper, manila envelopes, or paper bags are recommended packaging materials.

OBTAINING REFERENCE SAMPLES

Standard/Reference Sample—Physical evidence whose origin is known, such as blood or hair from a suspect, that can be compared to crime-scene evidence.

The examination of evidence, whether it is soil, blood, glass, hair, fibers, and so on, often requires comparison with a known standard/reference sample.

Although most investigators have little difficulty recognizing and collecting relevant crime-scene evidence, few seem aware of the necessity and importance of providing the crime lab with a thorough sampling of standard/reference materials.

PHYSICAL EVIDENCE

COLLECTION

CONTAINER

WHY?

victim’s clothingBlood-stained shirt

hairsoilCharred debris

glassdrugs

Plastic pill bottles or druggist fold

Plastic pill bottles

Wrapping paper, manilla envelopes, or paper bags

Paper bags

Air tight container

Sealed plastic bag

BASICS OF EVIDENCE COLLECTION:

1. Glass and metal should be collected in rigid containers

2. Hair, fibers, and small evidence should be collected in manila envelopes or sealed in plastic if there are no fluids present.

3. Bodily fluids should be air-dried and collected in porous containers such as paper bags.

4. Arson evidence (charred debris) should be collected in an air tight container to prevent evaporatioin.

LABELING & SEALING THE CONTAINER:1. Each container should be labeled with:

a. Name of collectorb. Date of collectionc. Time of collectiond. Description of evidence

2. A seal should be placed across the opening of the container with the initials of the collector n and the date.

EVIDENCE LAB

CHAPTER 2 NOTEBOOK CHECK

1. Ch 2 Reading Guide 2. Value of Evidence Video Questions 3. Crime Scene Investigation Notes 4. Ch 2 Review Questions (1-26) 5. Crime Scene Lab- “Don’t Touch the Evidence” 6. Collecting Physical Evidence Notes 7. Physical Evidence Collection Chart 8. Jonbenét Ramsey Documentary (30 Notes) 9. Evidence Lab 10. Autopsy & Death Notes 11. Autopsy Web Quest 12. Autopsy of a Banana