Chapter 2Chapter 2

Importance of EvidenceImportance of Evidence

Physical EvidencePhysical Evidence

Any material present at the crime Any material present at the crime scene, on the victims, or the suspect.scene, on the victims, or the suspect.

Can be at primary or secondary Can be at primary or secondary crime scene.crime scene.

Physical EvidencePhysical Evidence What will physical evidence found at the What will physical evidence found at the

crime scene do for the investigation?crime scene do for the investigation? May prove that a crime has been committedMay prove that a crime has been committed Establish key elements for a crimeEstablish key elements for a crime Link a suspect with a crime scene or a victimLink a suspect with a crime scene or a victim Establish the identity of a victim or suspectEstablish the identity of a victim or suspect Corroborate verbal witness testimonyCorroborate verbal witness testimony Exonerate the innocentExonerate the innocent Give detectives leads to work with in a caseGive detectives leads to work with in a case

Trace EvidenceTrace Evidence

Refers to physical evidence that is Refers to physical evidence that is found in small but measureable found in small but measureable amounts.amounts.

Examples include: Examples include: Strands of hairStrands of hair FibersFibers Skin cellsSkin cells

Testimonial EvidenceTestimonial Evidence

Oral or written statements given to Oral or written statements given to police as well as court testimony by police as well as court testimony by people who witnessed an event.people who witnessed an event.

Can include court testimony by Can include court testimony by people who witnessed an event.people who witnessed an event.

Testimony from _________ witnesses Testimony from _________ witnesses is very important in court.is very important in court.

Class vs. Individual Class vs. Individual CharacteristicsCharacteristics

Determining whether evidence is Determining whether evidence is from a group or a specific source is from a group or a specific source is crucial in investigations.crucial in investigations.

These associations may help These associations may help investigators determine a link investigators determine a link between the crime scene, parties between the crime scene, parties involved, and/or the evidence.involved, and/or the evidence.

Class CharacteristicsClass Characteristics

Recurring characteristics shared by Recurring characteristics shared by one or more objects in a group. one or more objects in a group.

All objects in this group will have the All objects in this group will have the exact same characteristics.exact same characteristics.

Ch. 2 Sec. 1 Notebook Ch. 2 Sec. 1 Notebook QuizQuiz

1) What is physical evidence?1) What is physical evidence? 2) What can physical evidence found at a 2) What can physical evidence found at a

crime scene do for the investigation?crime scene do for the investigation? 3) Define and give 3 examples of trace 3) Define and give 3 examples of trace

evidence.evidence. 4) What is testimonial evidence?4) What is testimonial evidence? 5) Determining whether _____ is from a 5) Determining whether _____ is from a

_______ or specific source is _____ in _____._______ or specific source is _____ in _____. 6) What is the difference between class 6) What is the difference between class

and individual characteristics?and individual characteristics?

ExampleExample

All size 10 Nike Air Force size 10 shoes All size 10 Nike Air Force size 10 shoes are manufactured to have a particular are manufactured to have a particular design. design.

All will have the same general All will have the same general appearance.appearance.

This is what distinguishes it from other This is what distinguishes it from other shoes.shoes.

If we find this print at a crime scene, it If we find this print at a crime scene, it will tell us the type of shoe but not the will tell us the type of shoe but not the person who owns it.person who owns it.

Individual Individual CharacteristicsCharacteristics

Random, unique features of an Random, unique features of an object that set it apart from other object that set it apart from other objects with the same class objects with the same class characteristics.characteristics.

All objects in the same group will not All objects in the same group will not have the same individual have the same individual characteristics.characteristics.

ExampleExample

Continuing with the footwear theme: Continuing with the footwear theme: cuts scratches, abrasions, foreign cuts scratches, abrasions, foreign objects (rocks), not general wear, etc. objects (rocks), not general wear, etc.

These characteristics are unique to 1 These characteristics are unique to 1 and only 1 particular shoe.and only 1 particular shoe.

Individual characteristics areIndividual characteristics are

very important pieces of very important pieces of

evidence.evidence.

Class vs. Individual Class vs. Individual Characteristics ActivityCharacteristics Activity

1)1) Tire trackTire track 8) Duct tape8) Duct tape

2)2) Blue hat Blue hat 9) Baseball bat9) Baseball bat

3)3) Social security cardSocial security card 10) License plate 10) License plate

4)4) Human skin cellsHuman skin cells 11) Fingerprint11) Fingerprint

5)5) # 2 Pencil with bite marks 12) Extension # 2 Pencil with bite marks 12) Extension cord cord

6)6) Empty Advil bottle 13) Nike Air Empty Advil bottle 13) Nike Air shoeprintshoeprint

7)7) .22 Rifle bullets (unfired).22 Rifle bullets (unfired) 14) Blood 14) Blood dropletdroplet

Forensic VocabularyForensic Vocabulary

MotiveMotive: the cause that induces people : the cause that induces people to complete a certain actionto complete a certain action

IntentIntent: the design or purpose to commit : the design or purpose to commit an actan act

CatalystCatalyst: substance that accelerates a : substance that accelerates a chemical reaction chemical reaction

Conclusive evidenceConclusive evidence: evidence that : evidence that may not be disputed and must be may not be disputed and must be accepted by the court as a definitive fact accepted by the court as a definitive fact

Forensic VocabularyForensic Vocabulary

FingerprintFingerprint: unique patterns created by : unique patterns created by skin ridges found on the palm sides of skin ridges found on the palm sides of fingers and thumbsfingers and thumbs

GeneGene: unit of inheritance consisting of a : unit of inheritance consisting of a sequence of DNAsequence of DNA

IndicatorIndicator: chemical used to determine : chemical used to determine the presence of an acid or a basethe presence of an acid or a base

Microscopic hair analysisMicroscopic hair analysis: procedure of : procedure of examining hair shafts for identifiable examining hair shafts for identifiable characteristicscharacteristics

Forensic VocabularyForensic Vocabulary

ChromatographyChromatography: process of separating : process of separating a chemical mixture into individual a chemical mixture into individual substancessubstances

Composite drawingComposite drawing: sketch of a suspect : sketch of a suspect produced from one or more eyewitnessesproduced from one or more eyewitnesses

CriminologyCriminology: study of criminal activity : study of criminal activity and how it is dealt with by the lawand how it is dealt with by the law

DNA profilingDNA profiling: process of testing to : process of testing to identify DNA patterns or typesidentify DNA patterns or types

Intro. To Forensic Intro. To Forensic AnthropologyAnthropology

AnthropologyAnthropology: study of humans, past : study of humans, past and presentand present

In forensics, it is studying the remains In forensics, it is studying the remains of humans in order to help solve a of humans in order to help solve a crime.crime.

How can studying remains of humans How can studying remains of humans be helpful in a forensic investigation?be helpful in a forensic investigation?

What things can be learned from What things can be learned from studying skeletal remains?studying skeletal remains?

Case Study # 9Case Study # 9

A robbery has occurred at 1216 E. Main A robbery has occurred at 1216 E. Main St. The front glass window was discovered St. The front glass window was discovered broken and all inventory has been stolen. broken and all inventory has been stolen. Small blood droplets were discovered on Small blood droplets were discovered on the sidewalk outside of the store. No blood the sidewalk outside of the store. No blood was discovered inside the store. There was discovered inside the store. There were no cameras inside the store. No were no cameras inside the store. No fingerprints or other pieces of evidence fingerprints or other pieces of evidence were found. Based on this information, were found. Based on this information, answer the following questions: answer the following questions:

Case Study # 9: Review Case Study # 9: Review QuestionsQuestions

1) What evidence was present?1) What evidence was present? 2) Can you solve the crime based on this 2) Can you solve the crime based on this

evidence? Why or why not?evidence? Why or why not? 3) List 2 things that this evidence can tell 3) List 2 things that this evidence can tell

you about the suspect. Why is this you about the suspect. Why is this important?important?

4) Which is more useful in blood evidence: 4) Which is more useful in blood evidence: DNA Sequence or Blood Type? Why?DNA Sequence or Blood Type? Why?

5) Is there anything suspicious about 5) Is there anything suspicious about finding the blood evidence on the outside finding the blood evidence on the outside instead of the inside of the store?instead of the inside of the store?

Case Study # 11Case Study # 11 Police receive a letter from an 8 year old Police receive a letter from an 8 year old

girl that goes by Lauren. Lauren has been girl that goes by Lauren. Lauren has been missing for 3 weeks. It had been presumed missing for 3 weeks. It had been presumed that she was kidnapped because on the day that she was kidnapped because on the day she went missing, her dad was released she went missing, her dad was released from prison. In the letter, the girl states from prison. In the letter, the girl states that she is fine and requests that police that she is fine and requests that police call off the search for her. It also states call off the search for her. It also states that she has found a new home where she that she has found a new home where she will be taken care of. The entire letter is will be taken care of. The entire letter is written in cursive, contains no written in cursive, contains no grammatical errors, and is signed Ellie grammatical errors, and is signed Ellie (her first name that no one calls her). (her first name that no one calls her).

Case Study # 11: Review Case Study # 11: Review QuestionsQuestions

1)1) Why was it presumed that Lauren Why was it presumed that Lauren was kidnapped?was kidnapped?

2) Who is the prime suspect in the 2) Who is the prime suspect in the crime?crime?

3) What is suspicious about the way the 3) What is suspicious about the way the letter is written?letter is written?

4) What is suspicious about the way the 4) What is suspicious about the way the letter is signed?letter is signed?

5) How could investigators verify that 5) How could investigators verify that this is indeed Lauren’s handwriting?this is indeed Lauren’s handwriting?

Case Study # 12Case Study # 12

A robbery has occurred at the First A robbery has occurred at the First National Bank in Bloomington, Indiana. 2 National Bank in Bloomington, Indiana. 2 masked men entered the bank at 9:00 A.M. masked men entered the bank at 9:00 A.M. carrying pistols and empty bags. They carrying pistols and empty bags. They forced all customers and employees onto forced all customers and employees onto the ground upon entering. After collecting the ground upon entering. After collecting the money, one of the men dropped his the money, one of the men dropped his wallet containing his social security card. wallet containing his social security card. Suspect # 2 took off his mask when exiting Suspect # 2 took off his mask when exiting the bank and his face was captured on the bank and his face was captured on camera. camera.

Case Study # 12: Review Case Study # 12: Review QuestionsQuestions

1)1) Where did the crime take place?Where did the crime take place? 2) What type of crime has occurred?2) What type of crime has occurred? 3) List the pieces of evidence that 3) List the pieces of evidence that

were found as well as if each has class were found as well as if each has class or individual characteristics.or individual characteristics.

4) How can the evidence be used to 4) How can the evidence be used to locate the suspects?locate the suspects?

5) Were there any witnesses? If so, 5) Were there any witnesses? If so, how would they be useful in solving how would they be useful in solving this case?this case?