People aren’t very good at detecting liars. Studies show that people’s hit rate for detecting lies (54%) is slightly above pure chance (50%), which is good news for liars, but bad news for you in the courtroom.

Why? Because people tend to pay attention to certain cues to determine if someone is lying, but these cues may mean something entirely different.

Take the “vocal immediacy” cue, for example. Vocal immediacy is the directness with which someone responds to a question. The more roundabout or vague the response, the more likely jurors will figure your witness is lying. However, your witness may simply be thinking out loud, which sounds roundabout. Or your witness may not know what to say, and rather than answer “I don’t know,” or “I don’t understand the question” may resort to a vague mulling which again, looks like lying.

Another cue is “uncooperativeness.” Jurors commonly assume that a witness being uncooperative is hiding something, or being dishonest. Yet often an uncooperative witness is one who argues with opposing counsel rather than answer the question asked, or attempts to force their view of the facts into every response, rather than let their attorney do the litigating.

Your best witness—among other things—responds directly to the question asked, and leaves the lawyering to the lawyer.

The best tool to help your witnesses get to jury-worthy credibility is to use videotaped role-play in preparing them to testify. You can’t afford to let your witnesses get away with behaviors that could be mistaken by the jurors as those of a liar.