Did your spouse just look up and to the left when you asked if anything was going on with that “other person”? Did your child provide few details when you asked “what were you doing out late last night?” Maybe they are lying.

But while it’s impossible to say with 100 percent certainty whether a person is lying (after all, if it were possible, our justice system would look a lot different, wouldn’t it?), there are clues and questioning strategies you can employ that can at least improve your chances of detecting deception. Scientific research shows that nonverbal behavior is not a good source of evidence.

In a recent interview with The Huffington Post, Clark Freshman, J.D., a professor of law at the University of California Hastings College of Law who also has a firm that trains lawyers and negotiators in lie detection,  shared some tips on how to tell if someone is lying to you.

“Via Huffington Post

Use what you do know to detect truth or deception.
An example: You were driving by your husband’s office at lunchtime, and noticed he was walking to his car with a beautiful woman you’ve never seen before. They are laughing and walking very closely together, but they don’t see you. Your suspicions are aroused, but you keep driving. That night, your husband comes home from work. If you ask a general question, such as “How was your day today?”, your husband might say, “Oh, it was just a regular day, I spent most of it at the office though a colleague from the old office stopped by for lunch.” Because of this volunteering of information, “maybe I wouldn’t be suspicious because the person is volunteering an innocent explanation, not realizing you were suspecting anything to begin with,” Hartwig explains.

But if your husband says, “Oh, I was in the office all day,” and you follow up by saying, “Oh, that sounds tough, you didn’t even have time for lunch?” and he says “No, I literally sat at my desk all day,” then that is a lot shadier. It doesn’t mean for sure that he’s lying or cheating — it’s possible his interaction with that woman just slipped his mind, or it was so insignificant he didn’t feel the need to tell you about it — but may suggest that he is trying to conceal information that he is potentially paranoid about.

Look for ‘soft spots.’
Freshman notes that while there are no surefire indicators that a person is lying, there are “soft spots” that signal someone is experiencing an emotion for some reason — that may or may not be related to deception. Signs of a soft spot could even mean that “there’s a reason you should be more caring or compassionate” to that person, he says.

One of these soft spots is the detection of microexpressions, or facial expressions of emotions that show up for less than a second on a person’s face. However, these microexpressions can be hard to detect for people who are not trained to recognize them, he notes.

Facial microexpressions were examined in a 2008 study in the journal Psychological Science, which involved having study participants look at images that naturally elicited different emotions (ranging from happiness because of a photo of puppies playing, to disgust because of a photo of a severed hand). The researchers found that some emotions were easier to fake than others — happiness was easier to fake than fear, for instance — and strange expressions, such as rapid blinking when the face otherwise looked sad, were also common when a person was trying to deceive.”

H/T: Huffington Post