One simply cannot read another person's mind. That is to say that it is impossible to telepathically penetrate another person's thoughts. What IS quite possible is cold reading. Some people are even gifted in this skill, but it is still a skill that is learnable.
BODY LANGUAGE
Reading body language is a significant skill. Ask any professional card player and they will tell you that nearly everyone reveals what they are thinking and feeling by the way they hold their body and the way they hold the features of their face. Some obvious signs, for instance, that someone is lying to you is that they may look up and to the left, they may touch there face, they will force smiles. Trained interrogators know more of these features of nonverbal communication. There is nothing paranormal in this skill. It's as significant and as real as learning a card player's "tells."
NONVERBAL VOCALIZATIONS
Listen to a person's speech patterns. When they make sounds but aren't saying anything, they are actually unconsciously revealing information to an observant listener. Perhaps the person is lying, but the person may actually be trying to tell you something that he or she isn't even aware of. Watch for other seemingly distracting bits of noise making. These are subtle and sometimes allow for significant insights into a person's thoughts.
VISUAL CLUES
Look for visible clues. There a re a million little things that we normally choose to ignore. Remember how Sherlock Holmes used to figure out stuff by noticing little details? How about Monk? You can do the same thing. Is a man wearing a wedding ring? Married, duh. But what if he has a tan line on his ring finger? Perhaps he was recently divorced; look for more clues. If his clothes are slightly wrinkled, maybe musty, then perhaps he has just come out of a long term relationship where the woman did those things for him. Perhaps he's trying to hide his married relationship; look for more clues. If he is guilty-looking or unusually nervous about being recognized, that might indicate that he is cheating.
Most "sniffers" or fraudulent telepaths have a whole bag of tricks for sniffing out these kind of insights. They are, above all, observant and meticulous. The really good cheats will use microphones and ear pieces, shills (accomplices) mingling with the pigeons, computer background checks, and all sorts of low-tech means of tricking a person to reveal more about themselves that they think.
Whatever the case, since no person has ever been able to answer a truly scientific challenge of their paranormal mind-reading ability, one can rule out the supernatural when it comes to mind reading.-