The Interrogation Methods and Questioning Techniques of Professional Investigators Can Help You Gain More—and Better—Information
An interrogation is all about generating knowledge—just like a journalistic interview, a due diligence process, a sales conversation, or price negotiations with a supplier. Knowledge is power: information reveals both opportunities and limitations.
Former FBI negotiator Chris Voss once said that a good negotiator enters a negotiation well-prepared, but an excellentnegotiator uses the negotiation itself to gather additional information.
But the truth is, most people don’t reveal everything in a conversation—whether out of economic interest, fear of consequences, shame, or self-protection. Sometimes the information is incomplete. Sometimes the person is lying—intentionally—or simply mistaken.
That’s why professional investigators ask themselves crucial questions before every interrogation:
- How do I get the witness or suspect to talk?
- What questions should I ask?
- How can I obtain meaningful insights—or even a confession?
- And how can I detect lies or identify genuine mistakes?
In a World of Google and AI, Human Insight Remains Invaluable
We live in a time when nearly every objective fact can be found with a quick Google search—or by asking a tool like ChatGPT or Gemini. But things are different when it comes to personal or emotional information.
You can’t Google whether someone really wants to buy from you—or whether they’re just fishing for a better offer to pressure their current supplier. ChatGPT won’t tell you why someone’s behaving irrationally—or what their gut is telling them.
And Google’s Gemini won’t help you decide whether a candidate is the right hire for your company. AI can’t easily tell you whether you’re being subtly manipulated in a conversation.
What Investigators Know—And Why It Matters Outside the Courtroom
Many interrogation principles can be applied far beyond the world of criminal investigations. The investigator steers the conversation—“Who asks, leads.” They use specific questioning techniques and must then assess the reliability of the other person’s statements.
Some witnesses or suspects share information willingly. Others lie, omit facts, or say nothing at all—whichever suits their interests best. Interrogation techniques can also help us spot lies and detect genuine errors in conversations. Who wouldn’t want to know if someone is telling the whole truth, twisting it slightly, or feeding you a complete fairy tale?
No wonder researchers have long explored how lies can be uncovered—in both theory and practice. Judges must regularly assess the truthfulness of statements in court. For investigators, a lie is often the lesser evil compared to a mistake.
Why? Because in both cases, the statement is false—once by accident, once on purpose.
But lies are usually easier to uncover than honest mistakes—because a lie is anchored to the truth, while a mistake often isn’t. The liar is intentionally misleading, while the person making a mistake doesn’t realize they’re wrong.
5 Interrogation-Inspired Tips for Better Information Gathering
- Speak in person. Verbal conversations usually yield more detail and relevance than written questionnaires.
- Show you’re prepared—but never reveal how much you really know. If necessary, suggest that you know more than you do.
- Take time to build rapport. Small talk and genuine connection can go a long way. Show your conversation partners respect and appreciation.
- Don’t judge the truth of a statement by the person delivering it. Even successful businesspeople lie—sometimes exceptionally well.
- Use follow-up conversations. Debriefing and informal chats often lead to even more insights.