Untitled Flashcards Set

Unit 2 Study Guide - Crime Scenes

1. Identify the job of each individual below (from the notes):

• Medical Examiner – Determines the cause and manner of death by examining bodies.

• CSI Unit – Responsible for collecting, processing, and analyzing crime scene evidence.

• Police Officer – First responders who secure the crime scene, ensure public safety, and begin the initial investigation.

• Detectives – Investigate crimes by gathering evidence, interviewing witnesses, and building cases.

• Specialist – Experts in specific fields such as trace chemistry, toxicology, or microscopy who assist in analyzing evidence.

• District Attorney (DA) – Responsible for prosecuting criminal cases and ensuring legal procedures are followed.

2. What are the steps of crime scene protocol?

1. Secure the crime scene.

2. Document the scene through photographs, video, and notes.

3. Collect fragile evidence first.

4. Gather all physical and trace evidence.

5. Properly package and label evidence.

6. Maintain the chain of custody.

3. What is the difference between physical evidence and trace evidence? What are some examples of trace evidence?

• Physical Evidence – Any tangible object related to the crime (e.g., weapons, fingerprints, toolmarks).

• Trace Evidence – Small materials transferred during a crime, such as fibers, paint, or gunpowder.

4. Who is the first to respond to a crime scene? What are at least 3 things they will do once they are on the scene?

• First Responder: Police Officer.

• Actions Taken:

  1. Secure the scene and ensure public safety.

  2. Call for medical assistance if necessary.

  3. Begin initial documentation and establish boundaries for investigation.

5. Why must video footage and photographs be taken at crime scenes?

To accurately document the scene before it is disturbed and provide a visual record for investigation and court proceedings.

6. Why should fragile evidence be collected first?

Because it can easily be lost, destroyed, or contaminated if not handled immediately.

7. What are some examples of acceptable containers used to collect evidence?

• Paper bags

• Plastic bags

• Jars

• Envelopes

8. What are some things an investigator must consider when bagging evidence?

• Prevent contamination.

• Use appropriate containers.

• Properly label and seal each item.

• Maintain chain of custody.

9. What is the term for determining where collected evidence is at all times?

• Chain of custody – A record of who has handled the evidence and where it has been transported.

10. What are the 4 types of patterns investigators use to search for evidence at a crime scene?

1. Grid

2. Spiral

3. Line

4. Zone

11. What is circumstantial evidence? How can it be used during a trial?

• Circumstantial Evidence – Indirect evidence that implies a fact but does not directly prove it.

• Use in Trial – Helps establish a connection between the suspect and the crime through inference.

12. What are some examples of circumstantial evidence?

• Latent fingerprints

• Shoe impressions

• DNA traces

13. What is the difference between class evidence and individual evidence?

• Class Evidence – Links to a group (e.g., type of shoe, car tire).

• Individual Evidence – Unique to a single person or object (e.g., fingerprints, toolmarks).

14. What are some examples of physical evidence?

• Toolmarks

• Latent prints

• Shoe impressions

15. Why are eyewitness testimonies important in a trial?

They provide firsthand accounts of the crime and help identify suspects.

16. What are some things that can affect eyewitness accuracy?

• Stress or trauma

• Lighting conditions

• Time elapsed since the event

17. How are children and the elderly associated with eyewitness accuracy?

• Children and the Elderly are more susceptible to suggestion, which can impact their accuracy.

18. What are 3 things that do not affect eyewitness accuracy?

1. Race

2. Gender

3. Social status

19. Why is it important to separate witnesses at a crime scene?

To prevent them from influencing each other’s accounts.

20. When is eyewitness testimony the most persuasive?

When the witness is confident and provides a consistent account.

21. What is the cause of most wrongful convictions?

Misidentification by eyewitnesses.

22. What is the difference between patent 2D and patent 3D dimensional prints?

• Patent 2D Print – A flat impression on a surface.

• Patent 3D Print – A deeper impression in a soft surface like mud.

23. What is the difference between:

• Neutral Pronation – Balanced foot movement with even weight distribution.

• Over Pronation – Excessive inward rolling of the foot.

• Under Pronation – Placing weight on the outer edge of the foot.

24. What is the wear pattern for each type of pronation?

• Neutral Pronation – Even wear along the foot.

• Over Pronation – Excessive wear on the inner side.

• Under Pronation – Wear on the outer edge of the foot.

25. What kinds of evidence can you get from shoe impressions?

• Shoe brand and size

• Walking or running patterns

• Weight distribution

• Possible involvement in a crime

26.How can you determine whether an impression came from a man or woman?

• Men’s Shoes – Larger, wider, heavier tread.

• Women’s Shoes – Narrower, lighter, often with high-heel impressions.

27. What are some things that cannot be determined from shoe impressions?

• Exact height of the suspect

• Exact weight of the suspect

28. What is the difference between positive impressions and negative impressions?

• Positive Impression – Transfers material onto a surface (e.g., mud on the floor).

• Negative Impression – Removes material, leaving an outline (e.g., a shoeprint in dust).

29. How can an investigator tell if the suspect was walking versus running or holding a body?

• Walking – Evenly spaced prints.

• Running – Deeper impressions at the toe, spaced farther apart.

• Carrying a Body – Asymmetrical pressure with dragging or scuff marks.

20. What are 2 things to analyze when looking at tire track evidence?

1. Tread pattern – Determines the make and model of the tire.

2. Wheelbase measurements – Helps determine the type of vehicle