1. Class Name, Instructor Name
Lasley & Guskos, Criminal Investigation: An Illustrated Case Study Approach 1ed
Chapter 3
THE PROCESS OF INVESTIGATING CRIME
Class Name, Instructor Name
Date, Semester

2. CHAPTER OBJECTIVES Describe the preliminary investigation
Describe the investigative process and the stages of criminal investigation
Explain the first responder’s duties during the preliminary investigation
Identify the investigator’s role during the preliminary investigation
Explain the proper methods of crime scene photography and videography
Explain the proper methods of crime scene sketching
Describe the proper ways of conducting a crime scene search

3. Describe the preliminary investigation
Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Describe the preliminary investigation

4. Preliminary Scene

5. Criminal Investigators
Detectives
Inspectors
Special
Agents

6. Criminal Investigators & Evidence
Physical Evidence: blood, fingerprints, soil, firearms, etc.
Testimonial Evidence: statements
Documentary Evidence: maps, notes, sketches

7. Physical Evidence

8. Traits of Investigators
Science: be familiar with scientific principle
Psychology:
Know how to deal with people of different backgrounds
Communication:
Must communicate clearly to persons of all cultures and backgrounds

9. Traits of Investigators
Law:
Solid understanding of legal requirements of specific crimes
Ethics:
Aware of consequences to their actions w/case involvement
Economics:
Decision making regarding cost-benefit analysis of case resolution

10. Investigative Team
Crime Scene Technician: evidence search and collection
Crime Scene Photographer:
Photo/video evidence
Dispatcher: communications personnel
Patrol Officer:
First responder to crime scene

11. Investigative Team Criminalist: Forensic Scientist:
Criminal scientist trained in biology, chemistry, etc.
Forensic Scientist:
Analyze crime scene evidence
Confidential Informant:
Provides police with information criminal in nature
Other Team Members:
EMT’s, firefighters, K9, etc.

12. Goals & Objectives of Criminal Investigation
CIA
C—establish whether a crime has been committed
I—identify suspects involved in the criminal activity
A—associate suspects, victims, and the crime scene

13. Cases Hot Warm Cold Offender still at large Near crime scene
Suspect fled scene
Scene still has fresh evidence
Cold
Year or more where nothing has changed
No suspect leads

14. Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Describe the investigative process and the stages of criminal investigation

15. Investigative Stages Investigative Stages Crime Detection
Preliminary Investigation
Follow-up
Investigation
Case Preparation and Prosecution

16. Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Explain the first responder’s duties during the preliminary investigation

17. First Responder’s Role
Note/Log Preliminary Call Information
Watch for vehicles and persons of interest within or leaving the crime scene
Scan, assess, and reassess for officer safety issues

18. First Responder’s Role
Assess and address emergency medical care issues
Control, identify, secure, and initially interview persons at the crime scene
Establish crime scene boundaries

19. First Responder’s Role
Identify and preserve crime scene evidence
Notify and brief investigators
Review and prepare final documentation

20. Identify the investigator’s role during the preliminary investigation
Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Identify the investigator’s role during the preliminary investigation

21. Investigator’s at the Crime Scene
Establish division of labor
Obtain information from first responders
Interview key individuals
Conduct a reassessment of the crime scene
Canvass the crime scene vicinity

22. Examining the Crime Scene
Map out the crime scene:
Rough sketch of key areas
Core—primary area of crime scene
Peripheral crime scene—inner area
Extended area
Perform a walk through:
Learn nature and quality of evidence
Develop plan for searching
Create staging area
Create storage area

23. Processing the Crime Scene
Evidence collection teams
Crime scene technicians
Physical crime scenes
Electronic crime scenes 23

24. Explain the proper methods of crime scene photography and videography
Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Explain the proper methods of crime scene photography and videography

25. Photographing a Crime Scene
Forensic photography
Resource for investigators
Document evidence from various angles
Relevant and material
Photo logs are kept
Photos tell a story
Specialized photographic techniques used by CSTs 25 25

26. Night Photography

27. Forensic Videography Introduction by investigator
Record from outside in
Move camera steady and slow
Use a zoom lens for key evidence pieces
Do not try to exaggerate a crime scene
Never edit original content 27 27

28. Explain the proper methods of crime scene sketching
Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Explain the proper methods of crime scene sketching

29. Crime Scene Sketch Locations Distances
Computerized and automated methods
Rough sketch created at crime scene
Elevated perspective
Finished sketch completed at the office of the detective 29 29

30. Crime Scene Measurements
Rectangular coordinates
Best for indoor crime scenes, 2 fixed points
Triangulation
Used anywhere, most precise, measurements taken at various angles
Baseline coordinates
Straight line measurements, used anywhere
Polar coordinates
Large outdoor crime scenes, datum point
Total station
Indoor/outdoor surveyor’s transit
Uses advanced electronic distance meter and imaging systems

31. Measuring the Crime Scene

32. Describe the proper ways of conducting a crime scene search
Learning Objectives
After this lecture, you should be able to complete the following Learning Outcomes
Describe the proper ways of conducting a crime scene search

33. Crime Scene Search Methods
Line or Strip—lanes or strips across a search area
Grid—double-strip technique
Spiral—concentric circles from inside out
Link—searches along paths most likely to contain evidence
Zone—artificially constructed

34. Crime Scene Searches

35. Completing the Crime Scene
After all evidence has been identified, collected, and processed this occurs:
Release of the crime scene
Final walk-through by detectives

36. CHAPTER SUMMARY
The primary role of criminal investigators is to focus on the specific aspects of evidence needed to establish whether or not a crime has been committed; and, if they do, to discover the necessary evidence to prove that a particular suspect committed or did not commit the crime. In addition to identifying crimes and criminal suspects, investigators must gather sufficient evidence to build cases that can be successfully prosecuted in a court of law.
The first stage of the investigative process involves the detection of a crime. The second stage of the investigative process begins with the preliminary investigation, which is initiated at the time authorities begin their response to the crime. The preliminary investigation comes to a close when the initial search of the crime scene is concluded. The third stage is the follow-up investigation, where further evidence is gathered to build a case. The fourth and last stage requires the investigators to use available evidence to build a case for prosecution.

37. CHAPTER SUMMARY
First responders have the following primary duties during the preliminary investigation: 1. Approaching the Crime Scene, 2. Entering the Crime Scene, 3. Controlling and Securing the Crime Scene, 4. Establishing Crime Scene Boundaries, 5. Preserving Crime Scene Evidence, and 6. Briefing the Investigators and Documenting the Crime Scene.
The investigator’s role at the crime scene is to facilitate and coordinate evidence gathering activities at the scene. This includes conducting a reassessment of the first responder’s crime scene setup, interviewing witnesses, coordinating a canvass of the crime scene vicinity, performing a preliminary walk-through of the crime scene, as well as processing and documenting the crime scene for available evidence.

38. 1. Line or Strip, 2. Grid, 3. Spiral, 4. Link, 5. Zone.
CHAPTER SUMMARY
Photographs are taken to create a permanent record of the crime scene and crime scene evidence. Photos of individual pieces of evidence are taken in a series that captures long-range, mid-range, and close-up images to tell the story of the crime committed, and to show the evidence within the context of the entire crime scene. Photographs are taken in color, with the exception of black-and-white images combined with oblique lighting to create contrast to capture the 3-D aspects of impression evidence such as footprints and tire tracks.
1. Rectangular Coordinates, 2. Triangulation, 3. Baseline Coordinates, 4. Polar Coordinates, and 5. Total Station Method.
1. Line or Strip, 2. Grid, 3. Spiral, 4. Link, 5. Zone.