THE CRIME SCENE GAVS 2 Crime Scene Investigation - PowerPoint Presentation

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THE CRIME SCENE

GAVS 2 Crime Scene Investigation

1

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SFS1. Students will recognize and classify various types of evidence in relation to the definition and scope of Forensic Science.

b. Distinguish and categorize physical and trace evidence (e.g. ballistics, drugs, fibers, fingerprints, glass, hair, metal, lip prints, soil, and toxins).

c. Determine the proper techniques to search, isolate, collect, and record physical and trace evidence. d. Evaluate the relevance of possible evidence at the site of an investigation. e. Organize relevant information to accurately develop and submit both scene and analysis reports.

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Learning Targets: I can

Describe how a crime scene should be secured, assessed, and examined.Describe the types of evidence collected at a crime scene.

Describe how crime scene evidence is collected and documented.List the various search patterns used at a crime scene when searching for evidence.

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Crime Scene Legal Issues

A crime is an act or omission that constitutes an offense and may be prosecuted and punished in a court of law.

Not all crimes are the same severity:Infraction/Violation – usually minor and generally punishable by a fine. Ex: traffic or parking ticket.Misdemeanor – less serious than a felony and punishable by no more than a year in jail. Ex: petty theft, first time DUI, leaving the scene of a crime.

Felony

– serious crime that is punishable by more than a year in jail and possibly the death penalty. Ex: murder.

Slide5

4th Amendment

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, the persons or things to be seized.

Provides protection against unlawful search and seizureApplies to ALL crimes.

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Evidence

Evidence – body of facts or information indicating whether a belief or proposition is true or valid. Two major classifications of evidence:

Class Evidence – Material that can be associated only with a group of items that share properties or characteristicsIndividual Evidence – Material that can be related to a single source or person, individualization always involves a comparison.

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Evidence (cont.)

Types of EvidenceDirect Evidence (Testimonial Evidence) – statements made under oath such as eyewitness accounts and expert witness statements.

Physical Evidence – Tangible items found at the crime scene, on the victim, or in the suspect’s possession, that prove a material fact. Ex: fingerprints, body fluids, gunshot residue.Indirect Evidence (Circumstantial Evidence) – neither proves nor disproves a fact in question, but provides as basis for inference. Ex: DNA left at a crime scene is considered indirect unless someone saw the person actually leave the sample of DNA because it could have been left at another time.

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Arrival at the Crime Scene

Upon arrival at a crime scene the first responding police officer to a crime scene is responsible for:

Acquiring medical assistance for injured victims

Medical

personnel avoid

disturbing evidence

and approach the victim by

an indirect

route.

Detaining

any potential suspects or

witnesses

Obtain s

tatements from victims, witnesses

, and suspects.

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Securing

the crime scene to the

greatest extent possibleThe boundary is sealed off, and guards are

posted at

the entry to the crime scene if needed.

All civilians and unauthorized personnel

are excluded

from the crime scene

.

Calling

for any additional personnel

needs such

as other officers and/or

forensic investigators

.

The personnel required depends upon

the nature

of the crime scene.

Arrival at the Crime Scene

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Recording

The Crime Scene

Photography,

sketches

, and

notes

are the three methods for crime-scene recording

. Ideally,

all three should be

employed

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Crime Scene Notes

Note taking begins when the investigator is contacted and requested to report to the crime scene.

The crime scene notes should begin with:

The identity of person who contacted

the investigator

Time of contact and arrival at the

crime scene

Preliminary case information

Personnel present on arrival and

those being

contacted

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Notes contain a personnel log, all observations made by the investigator, and the time observations were made.

Notes are taken in a uniform layout, concurrently as the observations are made.

Notes are written in a bound notebook in blue or black ink.

Crime Scene Notes

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Crime Scene Photography

Crime scene photographs should record the area in which the crime actually took place and all adjacent areas where important acts occurred.

The most important prerequisite for photographing a crime scene is for it to be in unaltered condition.

Each crime scene should be photographed as completely as possible in a logical succession. The sequence will show the overall scene first, then work down to individual pieces of evidence that jurors in the trial can easily relate back to the larger

scene.

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Crime Scene Photography

The four minimum photographs required at a crime scene

are: an overview photograph, a medium range photograph, a close-up photograph, and a close-up photograph with a scale.

Overview photographs of the entire scene and surrounding area, including points of exit and entry, are taken first.

Taken from the outside borders of the scene and from

various

angles

If the crime scene includes a body, photographs must show the body’s position and location relative to the entire scene.

Include a “visual tag,” an object recorded in

multiple overview

photographs, to help visually piece the

scene

together

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PHOTOGRAPHY

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Crime Scene Photography

Medium-range photographs show the layout of smaller significant areas of the crime

scene:

Taken with evidence markers in place to show the spatial relationships between and among pieces of evidence in greater detail than the overview photographs.

Include at least one photograph of the “center” of the scene.

In violent crimes, this usually includes the site where the victim was found and the surrounding area.

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Crime Scene Photography

Close-up photographs are taken last and show greater detail of individual objects or

evidence:

Taken at a 90º angle to the object, with and without evidence markers and scales.

Scales should be placed as close to the evidence as possible without affecting it in any way.

After the 90º photographs have been taken, photographs from other angles may be taken.

The most important close-up photographs are those depicting injuries and weapons lying near a body.

After the body is removed from the scene, the surface beneath the body should be photographed.

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Videotaping Crime Scenes

As with still crime scene photography, the crime scene video must include overview, medium-range, and close-up images.

A narrated crime scene video combines photography and notes.

However, it is important that only one person narrates and no side conversations are captured on the video.

Some video cameras can produce still photographs, but the quality is often poor.

Therefore, still photographs from a digital camera are still required.

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Surveying the Crime Scene

The

Walkthrough—initial

survey of the crime scene

Perpetrator’s

point of entry and exit are located.

Indirect

path is taken to the center of the crime

scene

.

Obvious

items of evidence are located

and documented

.

The

conditions of the scene are observed

and recorded

.

Special

attention is paid to item or conditions that

suggest

timing of the incident or do not appear to

belong

.

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Searching the Crime Scene

Line/Strip Search Pattern

One or two investigators start at the boundary of the crime scene and search in straight lines across to the other side of the crime scene.

Grid Search Pattern

Two or more investigators form a grid by searching in line patterns that overlap and are perpendicular to each other.

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Searching the Crime Scene

Spiral Search

PatternOne

investigators searches in a spiral path from the

center

of the crime scene to the boundary (outward) or from the boundary of the crime scene to the center (inward).

Wheel/Ray

Search Pattern

Several investigators search in straight lines from the center to the boundary (outward) or from the boundary to the center (inward).

Quadrant/Zone Search Pattern

The crime scene is divided into smaller sections (zones). One or more investigators are assigned to search each zone.

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Several

typical examples of crime-scene search patterns. The pattern selected normally depends on the size and locale of the scene and the number of collectors participating in the search.

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Searching the Crime Scene

Vehicle

Searches:

Investigators search interior and exterior of vehicle.

The vehicle may be searched at the crime scene or at the police department or crime laboratory garage.

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Sketching the Crime Scene

Crime scene

sketches:

Clearly show the layout of a crime scene

Illustrate the relationship in space of all significant items and features

Clarify objects and features already described in notes or shown in photographs

Show measurements over long distances and topography of outdoor scenes

Depict possible paths of entry, exit, and movement through the

scene

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The Rough Crime Scene Sketch

A rough sketch is created at the crime scene and contains an accurate depiction of the dimensions of the scene and shows the location of all pertinent objects and features.

All rough sketches

include:

Title block

with information on the case, crime scene, and person creating the sketch

Legend

with identity and dimensions of objects in the sketch

Compass

showing the North direction

Body

containing the sketch itself

Points of reference for objects can be shown by the distance measurements from two fixed points.

Slide26

Rough-sketch diagram of a crime scene

Courtesy

Sirchie Finger Print Laboratories, Inc., Youngsville,

NC:

www.sirchie.com

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The Finished Crime Scene Sketch

The finished sketch is created from the information in rough sketch, but it is

drawn to scale with care and concern for appearance.

The current standard method utilizes Computer-Aided Drafting (CAD) programs to create the finished sketch.

CAD programs also allow for the creation of three-dimensional finished sketches.

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FORENSIC SCIENCE: An Introduction by Richard Saferstein

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Finished-sketch

diagram of a crime scene.

Courtesy

Sirchie Finger Print Laboratories, Inc., Youngsville,

NC:

www.sirchie.com

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Room Sketch

Earlier, you drew a sketch of this classroom. Look over that sketch again and make corrections to it, including drawing it to scale and including a Title Block, legend, and Compass.

Slide30

Procedures for Collection

Often, many items of evidence are clearly visible but others may be detected only through examination at the crime laboratory.

For this reason, it is important to collect possible carriers of trace evidence, such as clothing, vacuum sweepings, and fingernail scrapings, in addition to more discernible items

.

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Investigators handle and process physical evidence in a way that prevents changes to the evidence through contamination, breakage, evaporation, accidental scratching or bending, or through improper or careless packaging.

The use of latex gloves, disposable forceps, and sanitized equipment reduces the chance for contamination.

Whenever possible, one should keep evidence in its original condition as found at the crime scene.

Procedures for Collection

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Packaging

Each different item or similar items collected at different locations must be placed in separate containers. Packaging evidence separately prevents damage through contact and prevents cross-contamination.

The well-prepared evidence collector will arrive at a crime scene with a large assortment of packaging materials and tools ready to encounter any type of situation.

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Disposable 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.

Alternatively, 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

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Sealable plastic evidence bags.

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

Evidence from arson scenes should be packaged in airtight metal or glass containers to prevent the loss of accelerant vapors.

Packaging

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If biological or bloodstained materials are stored in airtight containers, the accumulation of moisture may encourage the growth of mold, which can destroy the evidential value.

In these instances, the material should be allowed to air-dry before being packaged in wrapping paper, manila envelopes, or paper bags.

Packaging

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Contamination is a key concern during the collection of DNA-containing

specimens,

such as blood, saliva, sweat or skin cells. Contamination can occur either by introducing foreign DNA through coughing or sneezing onto evidence or if items of evidence are incorrectly placed in contact with each other during packaging.

To prevent contamination, the evidence collector must wear a face mask and lab coat, use disposable latex gloves and work with disposable forceps when collecting evidence that may contain DNA.

Disposable coveralls, shoe covers, and eye protection offer added precautions to avoid contaminating DNA evidence.

Packaging

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Chain of Custody

Chain of

Custody: A

list of all persons who came into possession of an item of evidence.

Continuity of possession, or the chain of custody, must be established whenever evidence is presented in court as an exhibit.

Adherence to standard procedures in recording the location of evidence, marking it for identification, and properly completing evidence submission forms for laboratory analysis is critical to chain of custody.

This means that every person who handled or examined the evidence and where it is at all times must be accounted for.

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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

.

Slide39

Departing the Crime Scene

The experienced lead investigator decides when all pertinent physical evidence has been recorded and collected at the crime scene.

A final survey is undertaken to

review

the scene visually and collect all evidence and equipment.

Following the final survey, the crime scene is released to the proper authorities.

FORENSIC SCIENCE: An Introduction by Richard Saferstein

39

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Submitting Evidence

Evidence is usually submitted to the laboratory either by personal delivery or by mail shipment.

Care must be taken in packaging evidence that will be sent by mail in order to prevent breakage or other accidental destruction during transit to the laboratory.

Most laboratories require that an evidence submission form accompany all evidence submitted. Case information provided on this form enables the laboratory analyst to make an intelligent and complete examination of the evidence.

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Crime

Scene Safety

Crime scenes frequently present the investigator with biological specimens of unknown origin.The investigator has no way of gauging what health hazards they may contain.

One must use caution and protection at all times.

Slide42

It is recommended that personnel always wear latex gloves and possibly chemical resistant clothing, Tyvek-type shoe covers, a particle mask/respirator, goggles, or face shields when potentially infectious material is present. Gloves should be changed often.

Personnel

should maintain a red biohazard plastic bag for the disposal of contaminated gloves, clothing, masks, pencils, wrapping paper, and so on.

Crime

Scene Safety

Slide43

When processing and collecting evidence at a crime scene, personnel should be alert to sharp objects, knives, hypodermic syringes, razor blades, and similar items

.

Eating, drinking, smoking, eating, and chewing gum are prohibited at the immediate crime scene.

Crime Scene Safety

Slide44

Wayne Williams Probability Assignment

Wayne Williams: The Use of Fiber Evidence ArticleWayne Williams Probability Study Questions

Slide45

Case Study: Donald and Marsha Levine

Conduct an internet search Complete a case study report using the Case Study Template

Slide46

Crime Scene Report Assignment

Using the Crime Scene Report WorksheetGo to http://secondstory.com/project/explore-a-crime-scene-panorama to view the crime scene.

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Class and Individual Evidence Review

Categorize each of the following as Class Evidence or Individual Evidence

FingerprintType AB+ Blood DNA from a blood spatterHair with no root or follicular tag attachedNew size 12 Nike shoe

Roll of duct tape found in possession of a suspect with a tear pattern that matches the tear pattern of duct tape found on victim’s bound hands.

Red clay soil evidence

Green T-shirt

New tire’s tread pattern

Levi’s 505 jeans

Worn size 8 Reebok shoes with ½” chunk of the lower left heel area of sole missing in the shape of a crescent

Hair with follicular tag attached

Lip print

Half of a matching note used in a bank robbery found in the trunk of suspect’s car

Slide48

Class and Individual Evidence Review Answers

Class Evidence

Individual Evidence

Type AB+ Blood

DNA from blood

spatter sample

New

size 12 Nike shoe

Roll

of duct tape found in possession of a suspect with a tear pattern that exactly matches the tear pattern of duct tape found on victim’s bound hands

Red clay soil

evidence

Worn size 8 Reebok shoe with a ½” chuck of the lower left heel area of sole missing in the shape of a crescent

Hair with no root or follicular tag

attached

Fingerprint

Green T-shirt

Hair

with follicular tag attached

New tire’s tread pattern

Lip print

Levi’s 505

Jeans

Half

of a matching note used in a bank robbery found in the trunk of a suspect’s car

Slide49

Forensic Evidence Review

Match the following:

Material that can be related

to a single source or person; involves comparison

Indirect Evidence

Material that can be associated only

with a group of items that share characteristics

Class Evidence

Evidence

that only provides a basis for inference about a disputed fact

Individual Evidence

Type of evidence that is also known

as direct evidence

Testimonial

Evidence

Slide50

Forensic Evidence Review Answers

Match the following:

Material that can be related

to a single source or person; involves comparison

Individual Evidence

Material that can be associated only

with a group of items that share characteristics

Class Evidence

Evidence

that only provides a basis for inference about a disputed fact

Indirect

E

vidence

Type of evidence that is also known

as direct evidence

Testimonial

Evidence

Slide51

Legal Issues and Evidence Collection Self-Assessment

Which amendment guards against unlawful search and seizure?

2nd Amendment1st Amendment4th Amendment

5

th

Amendment

Slide52

Legal Issues and Evidence Collection Self-Assessment

Which amendment guards against unlawful search and seizure?

2nd Amendment1st Amendment4

th

Amendment

5

th

Amendment

Slide53

Legal Issues and Evidence Collection Self-Assessment (cont)

Which is not an exemption to the requirement for a search and seizure warrant?

Risk to safetyMurder SceneObjects within an officer’s plain viewCar on a public road with probably cause

Slide54

Legal Issues and Evidence Collection Self-Assessment (cont)

Which is not an exemption to the requirement for a search and seizure warrant?

Risk to safetyMurder SceneObjects within an officer’s plain viewCar on a public road with probably cause

Slide55

Legal Issues and Evidence Collection Self-Assessment (cont)

This item of evidence is collected in sterile, clean gauze, dried and refrigerated as soon as possible.

HairBloodPaintDrugs

Slide56

Legal Issues and Evidence Collection Self-Assessment (cont)

This item of evidence is collected in sterile, clean gauze, dried and refrigerated as soon as possible.

HairBloodPaintDrugs

Slide57

Legal Issues and Evidence Collection Self-Assessment (cont)

This type of evidence is put into cellophane or plastic envelopes while being careful not to mark on it or deface it in any way.

DrugsBloodDocumentsFingerprints

Slide58

Legal Issues and Evidence Collection Self-Assessment (cont)

This type of evidence is put into cellophane or plastic envelopes while being careful not to mark on it or deface it in any way.

DrugsBloodDocumentsFingerprints

Slide59

Legal Issues and Evidence Collection Self-Assessment (cont)

This type of evidence is packed in heavy cardboard or wooden boxes before being sent to the lab and should not be loaded when packed in the box.

DrugsFirearmsBulletsPaint

Slide60

Legal Issues and Evidence Collection Self-Assessment (cont)

This type of evidence is packed in heavy cardboard or wooden boxes before being sent to the lab and should not be loaded when packed in the box.

DrugsFirearmsBulletsPaint

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Legal Issues and Evidence Collection Self-Assessment (cont)

Items of evidence are compared with a known or control sample known as:

Questioned SampleStandard Reference SampleComparison SampleSubstandard Reference Sample

Slide62

Legal Issues and Evidence Collection Self-Assessment (cont)

Items of evidence are compared with a known or control sample known as:

Questioned SampleStandard Reference SampleComparison SampleSubstandard Reference Sample

Slide63

Legal Issues and Evidence Collection Self-Assessment (cont)

Who secures the crime scene?

Medical ExaminerCrime Scene InvestigatorResponding OfficerDispatch

Slide64

Legal Issues and Evidence Collection Self-Assessment (cont)

Who secures the crime scene?

Medical ExaminerCrime Scene InvestigatorResponding OfficerDispatch

Slide65

Legal Issues and Evidence Collection Self-Assessment (cont)

When should an officer enter a crime scene risking contamination of the scene?

To measure the size of a murder weapon found on the ground.To help a victim who needs life-saving medical assistance.When noticing a document tacked to the front door that might be evidence.To answer a call from dispatch on his/her radio.

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Legal Issues and Evidence Collection Self-Assessment (cont)

When should an officer enter a crime scene risking contamination of the scene?

To measure the size of a murder weapon found on the ground.To help a victim who needs life-saving medical assistance.When noticing a document tacked to the front door that might be evidence.To answer a call from dispatch on his/her radio.

Slide67

Legal Issues and Evidence Collection Self-Assessment (cont)

Why is it important that scene personnel be trained in proper evidence collection?

So that they pass their crime scene investigation accreditation evaluations.If not collected properly, evidence may be considered tampered or destroyed and become inadmissible to court.There is no formal training required for evidence collection technique.Because evidence quotas will not be met for the year.

Slide68

Legal Issues and Evidence Collection Self-Assessment (cont)

Why is it important that scene personnel be trained in proper evidence collection?

So that they pass their crime scene investigation accreditation evaluations.If not collected properly, evidence may be considered tampered or destroyed and become inadmissible to court.There is no formal training required for evidence collection technique.

Because evidence quotas will not be met for the year.

Slide69

Legal Issues and Evidence Collection Self-Assessment (cont)

Evidence is always help secure and documented throughout collection and preservation. This is known as:

Custody of evidentiary dataChain of commandChain of custodyEvidence control

Slide70

Legal Issues and Evidence Collection Self-Assessment (cont)

Evidence is always help secure and documented throughout collection and preservation. This is known as:

Custody of evidentiary dataChain of commandChain of custodyEvidence control

Slide71

Canine Caper Lab

Canine Caper Lab instructionsGo to http://www.oercommons.org/courses/csi-the-experience-web-adventures/viewSet up an account