Say 2 - Criminal Investigation Overview

Criminal Investigation Objectives

• Criminal Investigator Responsibilities

  • Understand how, when, and where to look for evidence

  • Utilize the 5W1H framework:

  • Who

  • What

  • Where

  • When

  • Why

  • Sources of information include:

  • Evidence

  • Witnesses and Informants

  • Own training and experience

  • Technology advances in evidence collection and preservation

Reasoning Techniques in Criminal Investigation

Deductive Reasoning

• Definition: A reasoning approach that uses a "top-down logic" method.

• Process:

  • Start with an idea (conclusion) and test its validity through supporting premises.

  • Moves from the general to the specific.

• Conclusion Formation:

  • Based on the agreement of multiple statements (premises) assumed to be true.

  • Begins with an assumed premise and determines what else must be true based on that premise.

• Steps:

  • A. Identify a problem of interest.

  • B. Develop a theory to guide you.

  • C. Generate a hypothesis.

  • D. Make observations.

Inductive Reasoning

• Definition: A reasoning approach that uses a "bottom-up logic" method.

• Process:

  • Start with specific observations and work up to broader generalizations.

  • Look at evidence and draw conclusions based on observed patterns.

• Conclusion Formation:

  • Evidence is collected in the form of premises based on observations.

  • General conclusions are drawn from the collected evidence.

• Steps:

  • A. Identify a problem of interest.

  • B. Make multiple observations.

  • C. Develop a theory based on the observations.

• Reliability:

  • The reliability of a conclusion drawn from inductive reasoning depends on the completeness of the observations.

  • Example: penguin situation illustrating the potential gaps in inductive reasoning.