If you’ve ever watched a police procedural, you’ve probably been impressed that a brilliant detective could interrogate a suspect, pick up subtle clues that no one else can see and finally get a suspect to confess by catching them in a lie.

These TV shows and movies are impressive because they show a superhuman level of perception that seems too good to be true. And that’s because it is. While plenty of law enforcement officials are good at what they do, there is no way to reliably detect deception or ascertain the truth just by studying body language, “micro expressions” or tone of voice. Yet law enforcement agencies around the country are spending taxpayer dollars on self-proclaimed experts who assert that these techniques are real and can even be taught.

Earlier this summer, a hacking project known as “BlueLeaks” accessed a trove of law enforcement documents from around the U.S. and posted them online. Contained in those documents was information on training sessions given to police departments in various locations by a woman whose self-promoted abilities at reading suspects make her seem more like a psychic than an expert in human behavior.

Many of the techniques promoted in the training session are based on psychology theories that have long been discredited. Others are and have always been nothing more than junk science. Yet law enforcement agencies continue to take classes like these, at taxpayer expense, and use the techniques in their own practice.

At best, these “tricks” are a waste of time. At worst, they lead to a miscarriage of justice. It’s not possible to reliably determine who is lying and who is telling the truth without objective evidence. But it is very possible to decide that someone is lying, then wear them down over hours and days until they agree to confess. Unfortunately, the confession won’t be real, but the consequences very likely will be for the suspect.

If you have never been arrested before, it might be tempting to think that you can talk to and reason with law enforcement officers. But you simply cannot risk going into an interrogation without a criminal defense attorney by your side. As long as junk science is still being taught to police officers, you need to ensure that you have a strong legal advocate protecting your rights and freedom.