How Law Enforcement Can Tell If Someone is Lying

There is no single body movement, facial expression, or microexpression for deception. However, a combination of certain behaviors and expressions can strongly suggest a person is untruthful. Law enforcement and security officers are often trained to identify these nonverbal cues and act accordingly. The skills officers use to interpret lying body language can convert to the business world as well.  If you can get an idea of how honest someone is being, you can better negotiate deals, hire employees, and settle HR issues. 

Incongruent Responses Police Officers Look For

There is no universal gesture or expression for lying, meaning different people respond differently when questioned. To read a person’s behavior more accurately, you need to establish a baseline. Police officers or detectives establish a baseline by asking simple, straight forward questions. By doing so, they can gauge how a person normally communicates, carries their body, talks with their hand, and uses expressions. Then, they start asking relevant questions and look for changes in those behaviors. Incongruent responses can guide police officers as they discover the truth.

Microexpressions vs. Controlled Expressions

Microexpressions occur in a flash. They are uncontrolled, reflexive responses that people emote before their conscious brain takes over with controlled expressions. With practice, observers can catch these microexpressions, even though they last for only fractions of a second. It is usually too difficult and unnatural to constantly search for these cues, but you can pay extra attention to key points in a conversation.


For instance, microexpressions law enforcement look for are anger, fear, and surprise. They will pay particularly close attention when they ask bold questions, like “Did you know there were security cameras?” If fear flashes, they may be scared that they were caught on the camera, suggesting they were in fact at the crime scene. The officer can then use this nonverbal response to guide his questioning. 

Lying Body Language: Voice, Body, and Face

Truth leakage can seep out of a person’s voice, body, and face. There are tell-tale signs that a person is angry, sad, scared, contemptuous, and more– all of which can point towards deception if combined with other nonverbal cues. When people learn to identify these physical responses, they can compare them to what the person is saying to see if they match up.

Body Language and Business: How to Tell If Someone is Lying

Business professionals can use the same tactics as law enforcement to guide negotiations, HR conflict resolutions, or hiring interviews. It is crucial that the person you are dealing with isn’t aware you are scrutinizing their behavior. While law enforcement officers are at a disadvantage for making a person feel comfortable, business professionals can promote a more controlled environment that sets a person at ease. You can then more easily establish a baseline to interpret their behavior on. But remember, keep your knowledge and skills to yourself or people will start to guard their behavior around you. 


There is a lot to cover when discussing lying body language. Learning to read body language and micro expressions can be complex, but it doesn’t have to be difficult. Learn how to uncover a person’s true thoughts and feelings; John English offers a Reading Others Workshop: Discover Truth About Lies. There is limited space for this powerful two-day workshop on reading others and learning to make sense of truth and lies. Sign up today!