THEORY How to Develop and Test Investigation Theories Part 3

[BrentDaug]

## THEORY TESTING TECHNIQUES

### The Falsification Method

**Principle:** Try to DISPROVE your theory. If you can't, it grows stronger.

**Process:**
1. State your theory clearly
2. Identify what evidence would prove it wrong
3. Actively search for that contradictory evidence
4. If found, theory is false or needs revision
5. If not found, theory survives another test

**Example:**
- **Theory:** "Subject left work at 5:00 PM on March 15"
- **What would disprove it:** Security footage showing them leaving earlier/later, witness seeing them elsewhere at 5:00 PM, badge scan at different time
- **Search:** Review all security footage, interview witnesses, check electronic records
- **Result:** Badge scan confirms 5:03 PM exit - theory survives with minor time adjustment

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### The Alternative Explanation Challenge

**Principle:** For every piece of evidence, ask "What else could explain this?"

**Example:**
- **Evidence:** Car found abandoned near highway
- **Theory A explanation:** Driver left it there intentionally
- **Alternative explanations:**
- Car broke down, driver got ride from someone
- Driver had medical emergency, wandered away confused
- Driver was forced to abandon car by another party
- Car was moved there after driver left it elsewhere

**Value:** Prevents tunnel vision and reveals overlooked possibilities

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### The Timeline Test

**Principle:** Does your theory fit the known timeline?

**Process:**
1. Create detailed timeline of events
2. Map your theory onto that timeline
3. Check if theory's required events fit available time
4. Identify conflicts or impossibilities

**Example:**
THEORY: Subject drove from Work (Location A) to Park (Location B), then to Home (Location C)

TIMELINE TEST:
5:03 PM - Left work (Location A) [CONFIRMED]
5:45 PM - Seen at park (Location B) [WITNESS REPORT]
6:00 PM - Should arrive home (Location C) [EXPECTED]

DRIVE TIMES:
Work to Park: 25 minutes minimum
Park to Home: 35 minutes minimum
Total travel: 60 minutes

ANALYSIS:
5:03 PM departure + 25 min = 5:28 PM earliest park arrival
5:28 PM + 35 min = 6:03 PM earliest home arrival

CONCLUSION: Theory POSSIBLE but tight timing. Timeline fits if slight delay occurred.

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### The Evidence Weight Assessment

**Principle:** Not all evidence is equal. Weigh evidence by strength.

**Evidence Strength Scale:**

**STRONG EVIDENCE (High Weight)**
- Physical/forensic evidence with chain of custody
- Electronic records (phone logs, GPS, transactions)
- Video/photo evidence with verification
- Multiple independent witness confirmations
- Official documentation

**MEDIUM EVIDENCE (Moderate Weight)**
- Single credible witness statement
- Circumstantial but documented evidence
- Expert opinions with disclosed methodology
- Verified but incomplete records

**WEAK EVIDENCE (Low Weight)**
- Hearsay or second-hand accounts
- Uncorroborated witness statements
- Speculation or assumptions
- Rumors or unverified claims

**Example Weighting:**
THEORY: Subject met with unknown person before disappearing

SUPPORTING EVIDENCE:
- Text message: "Meeting someone at 5:30" [STRONG - electronic record]
- Witness saw subject with stranger [MEDIUM - single witness]
- Friend says subject mentioned meeting [WEAK - hearsay]

CONTRADICTING EVIDENCE:
- No appointment in calendar [WEAK - absence of evidence]
- Coworker says subject planned to go straight home [MEDIUM - witness]

ASSESSMENT: Theory PROBABLE (65%) - Strong electronic evidence outweighs contradictory witness statement.

 

THEORY  How to Develop and Test Investigation Theories Part 2

THEORY  How to Develop and Test Investigation Theories Part 4