THEORY How to Develop and Test Investigation Theories Part 1

[BrentDaug]

## INTRODUCTION

A theory is your working explanation of what happened in a case. Good theories are built on evidence, tested against facts, and refined as new information emerges. This guide teaches you how to develop sound theories and distinguish them from speculation.

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## WHAT IS A THEORY?

### Definition

An **investigation theory** is a testable explanation for events in a case, based on available evidence and logical reasoning. It proposes what happened, why it happened, and how it happened.

### Theory vs. Speculation

**THEORY (Evidence-Based)**
- Built on actual evidence
- Supported by multiple facts
- Can be tested against new information
- Changes when contradicted by evidence
- Example: "Subject left voluntarily because bank records show planned withdrawals, car was packed with belongings, and they told friends they were unhappy"

**SPECULATION (Guesswork)**
- Based on assumptions or hunches
- Little to no supporting evidence
- Cannot be tested or verified
- Persists despite contradictory evidence
- Example: "I think they were abducted by aliens because it seems mysterious"

 

THEORY  How to Develop and Test Investigation Theories Part 2