Friday 10/16/15 Aim:How do investigators classify physical

evidence?• Do Now: 1- Which amendment determines how evidence is collected from the crime scene?2- Identify 2 pieces of evidence that you consider MOST useful and LEAST useful to an investigation. Explain why.

• HW:Textbook page 29 question 15,16,17

Remember

• Evidence collected from the crime scene must be based on the 4th amendment

• Must have probative value– The evidence must be relevant– It must prove something

• Must be material– Relevant to the crime

What are the two types of evidence obtained from a

crime scene?

Types of evidence• Testimonial: eyewitness account

– Statement made under oath

• Physical Evidence: Any object or material relative to the crime

If you could only find one of the following pieces of evidence at a crime scene which would you choose? Why?

OR

If you could only find one of the following pieces of evidence at a crime scene which would you choose? Why?

OR

A. Classification of physical evidence

• Individual- An item of evidence that comes from a unique source

• Direct association

• Class- Items that share a common source

• Can be placed with other items sharing the same properties

Monday 10/19/15• AIM: How is physical evidence categorized?• Do NOW: Odor analysis: Casey Anthony

Trial. After reading answer questions in Choice A or Choice B which ever you feel more comfortable.

• HOMEWORK: Text read pages 34-36. answer questions 1,2,3 and 7 on page 50

• Write out the question followed by the answer

B. Individual Characteristics• Evidence that can be connected to a source

with a high degree of certainty– Examples: dental impressions

• Fingerprints• Bullets• Handwriting• DNA

C. Class Characteristics• Evidence that can only be associated with a group and

NEVER with a single source– Examples

• Paint chips from a car• Blood Type (A, B, AB, O)

• Weakness of forensic science• More likely to find this type of evidence at a crime scene

Class

Individual

Class

Individaul

D. Probability

• The greater the frequency of an occurrence, the less significance can be attached to its value.

– E.g. A hit and run occurred in 1969. The car was described as a 1968 yellow VW Beetle. Does this information help investigators?

– How may it be different if the hit and run occurred today?

E. Types of Physical Evidence

Transient evidence is temporary; easily changed or lost; usually observed by the first officer at the scene.

Conditional evidence is 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.

Associative evidence is something that may associate a victim or suspect with a scene or with each other; e.g., personal belongings.

Tuesday 10/20/15• AIM: How is physical evidence characterized?• DO NOW: 1-Explain why blood is both class and

individual evidence.• 2- Explain the difference between individual and

class evidence and give an example of each• HOMEWORK: Text page 50 questions 5,6,12

and 13• Last nights read 34-36 hw 1,2,3 and 7 pg 50

Examples of transient, conditional and associative

evidence

Casey Anthony Trial: Air Samples from Trunk Could Be O.J. Simpson Moment - ABC News

Examples of Transient Evidence

Odor—, perfume, gasoline, burning, explosives, cigarette 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

Examples of Conditional Evidence

Light—headlight, lighting conditions, lights on or off

Smoke—color, direction of travel, density, odor

Fire—color and direction of the flames,

Location—of injuries or wounds, of bloodstains, of the victim’s vehicle etc.

Vehicles—doors locked or unlocked, windows opened or closed, radio off or on, odometer mileage

Body—position and types of wounds

Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle

Examples of Associative Evidence

• A text message or phone call between victim and suspect

• The victims ID found in the suspect pocket• A lock of victims hair found at the suspect

home

Comparing different types of evidence.

• Working with a partner, complete the worksheet comparing different forms of evidence

• 6 minutes.

A. Classify each of the following piece of evidence as transient, associative or

conditional evidence1. The room smelled of cigarette smoke.2. The kitchen door was opened.3. An earring was found in the kitchen that did not belong to anyone in the house.4. The lights in the kitchen were turned on.5. The body was found face down in the kitchen.6. The arriving officer reported that the coffee pot was hot.7. There were two blood drops leaving the kitchen into the family room which did not

match the family members.8. In the family room a pair of gloves were also found.9. The sofa was turned away from the television.10. There was a strong smell of perfume coming from the sofa

A. Classify each of the following piece of evidence as transient, associative or conditional evidence

1. The room smelled of cigarettes.2. The kitchen door was opened.3. The lights in the kitchen were turned on.4. The body was found face down in the kitchen.5. The arriving officer reported that the coffee pot was hot.6. An earring was found in the kitchen.7. There were two blood drops leaving the kitchen into the family room.8. In the family room a pair of gloves that did not belong to ANY family

memberswere also found.9. The sofa was turned away from the television.10. There was a strong smell of perfume coming from the sofa.

Transient

Conditional

Conditional

Conditional

Transient Associative

Conditional

Conditional

Associative

Transient

Summary – Ticket out

1. Describe the difference between individual and class evidence.

2. List 2 examples of each type.3. Define trace evidence and give one

example.

Wednesday 10/21/15

• AIM: How can we identify evidence as individual or class?

• DO NOW: You are called to a crime scene and notice the door has been forcefully opened. What type of evidence would you expect the suspect to have and how could you connect it to the broken door?

• HOMEWORK: Lab analysis • Text page 50 questions 5,6,12 and 13

Presentation "Dr. Edmond ⚡Locard: Every criminal can be connected to a crime by small particles carried from the scene. Whenever 2 objects come in contact with one another,"