Field manual · Interviews · 4 min read
How to interrogate suspects and catch a lie
Suspects rarely confess. They over-explain, they volunteer detail nobody asked for, and they answer a slightly different question than the one you put. Interrogation is about noticing that.
Ask the boring question first
Start with something plain and verifiable: where were you, who saw you, what time did you leave. You are not hunting for a confession — you are locking in a version of events they will have to keep consistent for the rest of the interview.
Use evidence as a hinge, not a hammer
Naming a piece of evidence too early lets a suspect build their story around it. Ask your open questions first, then introduce the object and ask them to fit it into the account they just gave you.
Three tells worth chasing
In a written interrogation the tells are textual rather than physical.
- Unrequested detail: an alibi with a suspiciously vivid, checkable prop.
- Deflection: they answer about someone else's behaviour instead of their own.
- Shifting time: the same evening described with different hours to different questions.
Cross-reference before you re-ask
Take one suspect's claim about another suspect and put it to that person directly. Contradictions between two accounts are far more useful than anything a single person tells you about themselves.
Questions from the bullpen
- What questions should I ask a suspect first?
- Ask for their movements and their relationship to the victim before anything accusatory. Those two answers give you a baseline you can test everything else against.
- How many times should I question the same suspect?
- Twice is usually right: once early to record their story, once late with evidence in hand to see whether the story survives contact with the facts.