Crime Scene Basics
CSI Team & Applications
Locard's Principle
Types of Evidence
The 7 S's
100

100: What is the main goal of crime scene investigation?

100: To recognize, document, collect, analyze, and preserve evidence to reconstruct the crime and identify those involved.

100

100: Crime scene investigation teams include both scientific and legal professionals. True or False?

100: True

100

100: What is trace evidence?

100: Small pieces of physical material transferred during contact.

100

100: What is direct evidence?

100: Evidence that directly proves a fact, such as eyewitness testimony.

100

100: What does the first “S” in the Seven S’s stand for?

100: Secure the scene

200

200: What does it mean for evidence to be reliable?

200: Evidence is consistent and produces the same results when tested repeatedly.

200

200: Name two professionals who may be part of a crime scene investigation team.

200: Police officers, detectives, crime scene investigators, forensic scientists, medical examiners (any two).

200

200: Give two examples of trace evidence.

200: Hair, fibers, glass, soil, paint, pollen (any two).

200

200: What is circumstantial evidence?

200: Evidence that indirectly suggests a fact and requires inference.

200

200: What does “Survey the scene” involve?

200: Observing the scene to understand what happened and identify evidence.

300

300: What does it mean for evidence to be valid?

300: Evidence is relevant and actually proves or supports a fact in the case.

300

300: What is a staged crime scene?

300: A crime scene that has been altered to mislead investigators.

300

300: State Locard’s Principle of Exchange.

300: Whenever two objects come into contact, there is an exchange of materials.

300

300: What is the difference between class evidence and individual evidence?

300: Class evidence narrows to a group; individual evidence can identify a single source.

300

300: What is “Sketch the scene” and why is it important?

300: A scaled drawing showing evidence locations to help with reconstruction.

400

400: Why must crime scene evidence be handled carefully from the moment it is discovered?

400: To prevent contamination, loss, or damage that could make evidence inadmissible in court.

400

400: List three more commonly staged crime scenes.

400: Suicide, burglary, arson, accidental death (any three).

400

400: According to Locard’s Principle, what do exchanged materials indicate?

400: That a suspect was present at the scene or that two objects came into contact.

400

400: Give one example of class evidence and one example of individual evidence.

400: Class—blood type, hair (without root bulbs), fibers, pollen, etc.; Individual—DNA or fingerprints.

400

400: What is chain of custody and why is it essential?

400: Documentation showing who handled evidence; it ensures integrity and admissibility in court.

500

500: Identify at least five possible major errors a sketch artist could make.

500: Not measuring the room, missing items in the room or not measuring their exact placement based on "fixed points", not identifying "fixed points", not triangulating or giving perpendicular distances to evidence from "fixed points", not drawing final sketch to scale, not including the north arrow, crime scene location, date, etc.

500

500: List two indicators that a crime scene may have been staged.

500: Evidence inconsistent with injuries, lack of forced entry, items placed unnaturally, contradictory statements (any two).

500

500: Explain how trace evidence can connect a suspect, a victim, and a crime scene simultaneously. 

500: Trace evidence from multiple sources can link all parties through material exchange between each of them and the crime scene(s).

500

500: Blood type is class evidence—explain how it can still be useful in an investigation.

500: It can eliminate suspects and narrow the pool of possible contributors.

500

500: List all seven S’s of crime scene investigation IN ORDER.

500: Secure the scene; Separate witnesses; Scan the scene; See (photograph) the scene; Sketch the scene; Search for evidence; Secure and collect evidence.