How to Pass OVM3701: Investigative Principles for Policing III (2026 Guide)

Module: OVM3701 (Investigative Principles for Policing III)
Type: Semester Module
Focus: Expert Evidence, Modus Operandi, and Specific Crimes (Arson, Stock Theft, Perjury)

Introduction

If you have made it to third year, you know the basics. OVM3701 takes you deeper into the “Art of Investigation.”

This module teaches you how to work with experts (like ballistics and biology), how to interview suspects effectively, and how to investigate specific, complex crimes.

The 5 Core Pillars

Based on the Study Guide, the exam usually focuses on these key areas. You cannot pass without mastering them.

1. Expert Evidence (Learning Unit 1)

You need to know who to call to the crime scene.

Forensic Medicine: Pathologists (time/cause of death).
Forensic Biology: DNA, hair, and blood analysis.
Forensic Chemistry: Toxins (poison) and accelerants (arson).
Ballistics: Firearms and tool marks.
The Golden Rule: Experts analyze; Investigators safeguard. You must know how to maintain the Chain of Custody.

2. Modus Operandi (MO) (Learning Unit 2)

Criminals are creatures of habit.

Trademarks: What did they do before, during, and after the crime? (e.g., Cutting the fence in a specific way).
The Value: MO helps link cases (serial offenders) and predict future targets.

3. Statements & Confessions (Learning Unit 3)

This is the legal minefield. You must know the difference between:

Warning Statement: Taken from a suspect.
Admission: Admitting a fact (unfavorable), but not guilt.
Confession: Unequivocal admission of guilt (must be taken by a Magistrate or Commissioned Officer).
Pointing Out: A suspect showing the police the scene.

4. Interviewing vs. Interrogation (Learning Unit 4)

Interviewing: Gathering info from willing witnesses/victims.
Interrogation: Getting the truth from unwilling suspects.
Techniques: Know the different approaches (Direct, Indirect, Emotional, and the “Pessimistic” technique).

5. Specific Crimes (Units 7, 8, 9)

You will likely get a scenario question on one of these:

Perjury: Lying under oath. (Know the difference between Common Law and Statutory Perjury).
Stock Theft: Stealing livestock/produce. (Know the Stock Theft Act 57 of 1959).
Arson: Unlawful burning of immovable property. (Look for the “inverted cone” burn pattern and accelerants).

My Top Tips for Distinction

1. Use the “Scenario” Method
The exam often gives you a story (e.g., “A barn burned down…”). You must identify the crime (Arson), the expert needed (Forensic Chemistry for accelerants), and the procedure (cordon off, photograph the smoke color).

2. Memorize the “MISS” for Informers
When dealing with informers (Learning Unit 6), remember the MISS (Minimum Information Security Standards). You must protect their identity and safety at all costs.

3. Know Your Experts
Don’t just say “Call an expert.” Be specific.

Blood on a shirt? Forensic Biologist.
Forged signature? Questioned Document Examiner.
Bullet casing? Ballistics Expert.

Conclusion

OVM3701 is about being a professional investigator. It moves beyond “who did it” to “how can we prove it in court using science and psychology.”

Good luck with your investigation!