Types of Investigation Interviews
| Interview Type | Subject | Primary Goal | Approach |
|---|---|---|---|
| Information gathering | Witnesses, colleagues | Collect factual information | Cognitive interview, open questions |
| Complainant interview | Whistleblower or reporter | Understand the allegation fully | Empathetic, structured, protective |
| Subject interview | Person under investigation | Obtain their account; test against evidence | PEACE model; structured challenge |
| Expert interview | Technical specialist | Understand a specific system or process | Technical, detailed, non-confrontational |
The Cognitive Interview — Maximizing Witness Recall
Cognitive interviewing is a research-based technique developed to enhance the completeness and accuracy of eyewitness accounts. It uses specific mental reinstatement techniques to help witnesses access memories more fully:
- Mental reinstatement of context: Ask the witness to mentally return to the time, place, and emotional state of the event before describing it
- Report everything: Encourage reporting even partial memories — what seems insignificant to the witness may be critical to the investigation
- Recall in varied order: Ask for the account to be recalled in reverse or from a different starting point — this disrupts narrative fabrication and reveals additional genuine detail
- Change perspective: Ask the witness what they think another person present would have seen or heard
The PEACE Model in Practice
Preparation
Know the evidence thoroughly before entering the interview room. Prepare a written interview plan including: the key topics to cover, the questions to use for each topic, and the evidence available to address each topic. Plan the logistics — location, duration, recording, the presence of legal counsel.
Engage and Explain
The opening phase establishes rapport and sets the procedural context. Introduce yourself and any colleagues present, explain the purpose of the interview, confirm the recording arrangements, and ensure the subject understands their rights and the interview process. A professional opening creates the environment for a productive account.
Account — The Core of the Interview
- Free narrative phase: Begin with an open question — "Please tell me everything about your involvement in the procurement process for [specific contract]." Then stop talking and listen. The free narrative reveals what the subject volunteers without prompting.
- Structured questioning phase: Use TED questions (Tell, Explain, Describe) to expand on specific elements of the narrative. Avoid leading questions.
- Challenge phase: Where the subject's account conflicts with documented evidence, present the evidence and invite their explanation. "The bank records show that payment was made to Account X on [date]. You have told me that you did not authorize any payment to this vendor. Can you explain that?"
Statement Analysis Red Flags
Legal and Ethical Boundaries
- No threats, inducements, or promises — these render admissions inadmissible and expose investigators to personal liability
- Caution statement must be given to subjects who may incriminate themselves, aligned to Nigerian Evidence Act requirements
- The right to have legal counsel present must be communicated and respected for all suspect interviews
- Recording — audio or video — should be obtained with proper consent and stored as part of the evidence file
Key Takeaway
Professional fraud interviewing is a discipline built on preparation, structure, and ethical conduct. Investigators who master the PEACE model, understand cognitive interview techniques, and know the difference between evidence-based challenge and improper pressure consistently obtain more reliable information — and produce evidence that survives legal scrutiny — than those who rely on confrontational tactics.
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