0. Chapter 2 Vocabulary Physical Evidence Chain of Custody
Any object that can establish that a crime has been committed or can link a crime and its victim or its perpetrator.
Chain of Custody
A list of all people who came into possession of an item of evidence.
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.
Buccal Swab
A swab of the inner portion of the cheek; cheek cells are usually collected to determine the DNA profile of an individual.
Substrate Control
Uncontaminated surface material close to an area where physical evidence has been deposited. This sample is to be used to ensure the surface on which a sample has been deposited does not interfere with laboratory tests.

1. SEARCH METHODS Line or strip method—best in large, outdoor scenes
Grid method—basically a double-line search; effective, but time-consuming
Zone method—most effective in houses or buildings; teams are assigned small zones for searching
Spiral method—may move inward or outward; best used where there are no physical barriers

2. Types of Evidence Two general types:
Testimonial—a statement made under oath
Direct evidence or Prima Facie evidence
Physical—any object or material that is relevant in a crime
Indirect evidence
Examples: hair, fiber, fingerprints, documents, blood, soil, drugs, tool marks, impressions, glass.

3. Value of Physical Evidence
Generally more reliable than testimonial
Can prove that a crime has been committed
Can corroborate or refute testimony
Can link a suspect with a victim or with a crime scene
Can establish the identity of persons associated with a crime
Can allow reconstruction of events of a crime

4. Reconstruction Physical Evidence is used to answer questions about:
what took place
how the victim was killed
number of people involved
sequence of events
A forensic scientist will compare the questioned or unknown sample with a sample of known origin.

5. Types of Physical Evidence
Transient Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene
Pattern Evidence—produced by direct contact between a person and an object or between two objects
Conditional Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event
Transfer Evidence—produced by contact between person(s) or object(s), or between person(s) and person(s)
Associative Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings
DISCUSS WITH A NEIGHBOR AND COME UP WITH 2 EXAMPLES OF TRANSIENT, PATTERN, OR CONDITIONAL EVIDENCE.
—Lee and Labriola in Famous Cases, 2001

6. Examples of Transient Evidence
Odor—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke
Temperature—surroundings, car hood, coffee, water in a bathtub, cadaver
Imprints and indentations—footprints, teeth marks in perishable foods, tire marks on certain surfaces
Markings

7. Examples of Pattern Evidence
Pattern Evidence—most are in the form of imprints, indentations, striations, markings, fractures or deposits.
Clothing or article distribution
Gun powder residue
Material damage
Body position
Tool marks
Modus operandi
Blood spatter
Glass fracture
Fire burn pattern
Furniture position
Projectile trajectory
Tire marks or skid marks

8. Examples of Conditional Evidence
Light—headlight, lighting conditions
Smoke—color, direction of travel, density, odor
Fire—color and direction of the flames, speed of spread, temperature and condition of fire
Location—of injuries or wounds, of bloodstains, of the victim’s vehicle, of weapons or cartridge cases, of broken glass
Vehicles—doors locked or unlocked, windows opened or closed, radio off or on (station), odometer mileage
Body—position, types of wounds; rigor, livor and algor mortis
Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle

9. Classification of Evidence by Nature
Biological—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacterial, fungal, botanical
Chemical—fibers, glass, soil, gunpowder, metal, mineral, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer
Physical—fingerprints, footprints, shoe prints, handwriting, firearms, tire marks, tool marks, typewriting
Miscellaneous—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification

10. Evidence Characteristics
Class—common to a group of objects or persons
Individual—can be identified with a particular person or a single source
Fingerprints
Blood DNA Typing

11. Class vs Individual Evidence
Which examples do you think could be individual evidence?

12. COLLECTING AND PACKAGING EVIDENCE
One individual should be designated as the evidence collector to ensure that the evidence is collected, packaged, marked, sealed, and preserved in a consistent manner
Each item must be placed in a separate container, sealed, and labeled
Most fragile is collected and packaged first
Different types of evidence require specific or special collection and packaging techniques
The body is the property of the coroner or medical examiner. The collection of evidence on the body is done by that department

13. PACKAGING
Most items should be packaged in a primary container and then placed inside a secondary one. These are then placed inside other containers such as paper bags, plastic bags, canisters, packets and envelopes depending on the type and size of the evidence.

14. CHAIN OF CUSTODY
There must be a written record of all people who have had possession of an item of evidence.
The evidence container must be marked for identification
The collector’s initials should be placed on the seal
If evidence is turned over to another person, the transfer must be recorded.

15. Chapter 2 Vocabulary Rough Sketch Finished Sketch
A draft representation of all essential information and measurements at a crime scene. This sketch is drawn at the crime scene.
Finished Sketch
A precise rendering of the crime scene, usually drawn to scale.

16. CORPUS DELICTI “Body of the Crime”
You must prove
that a crime occurred
that the person charged with the crime was responsible for the crime
Source of Evidence
Body
Primary and/or Secondary Crime Scene
Suspect(s)

17. CRIME SCENE TEAM
A group of professional investigators, each trained in a variety of special disciplines.
Team Members
First Police Officer on the scene
Medics (if necessary)
Investigator(s)
Medical Examiner (if necessary)
Photographer and/or Field Evidence Technician
Lab Experts

18. CRIME SCENE INVESTIGATION
Based on the scientific method and the Locard Exchange Principle, logic and forensic techniques
Involves:
Recognition—scene survey, documentation, collection
Identification—comparison testing
Individualization—evaluation and interpretation
Reconstruction—reporting and presenting

19. PROCESSING A CRIME SCENE
Isolate and secure the scene
Document the scene
Search for evidence
Collect and package evidence, maintaining the chain of custody
Submit evidence to the crime lab

20. FIRST OFFICER ON THE SCENE
A Assess the crime scene and assist those hurt
D Detain the witness
A Arrest the perpetrator
P Protect the crime scene
T Take notes

21. CRIME SCENE SURVEY
Walk-through—performed by the crime scene investigator, the first officer and sometimes the lead detective
Purpose:
Mentally prepare a reconstruction theory
Note any transient or conditional evidence that could change over time.
Note weather conditions
Note points of entry or exit, as well as paths of travel within the crime scene
Record initial observations of who, what, where, when, and how
Identify special needs within the crime scene for personnel, precautions or equipment and notify superior officers or other agencies

22. DOCUMENTATION
Notes—date and time, description of the location, weather and environmental conditions, description of the crime, location of the evidence relative to other key points, the names of all people involved, modifications that have occurred and other relevant information
Photography—photos of scene and surroundings, mid-range to close-up photos with various angles of each piece of evidence, photos as viewed by any witnesses.
Sketches—inclusion of date, time, scale, reference points, distance measurements, names of investigators, victims, suspects, and a legend (key)
Videography—allows narration (non-subjective) to be included

23. CRIME SCENE SKETCH N Date: August 14, 2005 Criminalist: Ann Wilson
Time: 11:35 am Location: Rockledge Dr, St. Louis, Mo. N

24. Guest Speaker Questions
Sgt. Katherine Scheimreif from the CMPD will be our guest speaker on September 16
Sgt. Scheimreif is the Unit Leader of the Crime Scene Search team
Come up with 2 questions that you could ask her based on what we have learned so far or that directly relate to a crime scene

25. Chapter 1 Review
If your group is waiting to complete the lab then you can work on the Chapter 1 Review questions, #1-29 on pages 33-34

26. Recording a Crime Scene Lab
Read over the background information and instructions of the lab so that your group will be prepared when you enter the crime scene.
Determine who will be completing the following tasks in your group:
Sketcher – complete the sketch
Photographer- take all photographs that are needed
Recorder – take measurements of crime scene and record data in the data table
Manager (if extra person) – make sure group completes all required parts; place numbered markers and help others as needed

27. Recording a Crime Scene Lab
When you have left the crime scene, complete the procedures for after the crime scene.
Be sure to work together as a team to complete the sketch and to go through the photographs.