How do you catch a person who is lying to you?

How do you catch a person who is lying to you? Is it possible to know when someone is saying the truth and when not? Psychologists have tried to find ways to get hold of a person who is deceitful. But is it possible to get into someone's heart? We don't know for sure. But for any action, there are strong and visible reactions. Lies are harmful and can affect someone's life. Cheaters and fraudsters are trained to be dishonest, and very expertly. They even established the lie is a truth by using various tactics. Many people are innocent, so they believe the other person's lie easily.
There is a machine called a lie detector which can help you find out if someone is lying. But it is not possible to ask everyone to undergo a lie detector test. Therefore it is important to find out with our own naked eyes whether a person is saying the truth. When a person is angry there are evident signs on his face. If a person is tired, we can see it from his body language. Psychologists worked on such signals and have found a way to detect a lie.
Saying what is in our minds and what we believe to be true doesn't take much effort. It comes out smoothly. Unless we want to cover up some fact or change the factual statement, our gestures would be seamless. Only when one has to convince the other person what he himself knows is not true then he needs to make the extra strong attempt. In a way, misrepresenting facts is difficult. It always creates fear in the speaker's mind.
As per Science Daily, when a person lies, they experience a "Pinocchio effect," which is an increase in the temperature around the nose and in the orbital muscle in the inner corner of the eye. In addition, when we perform a considerable mental effort our face temperature drops, and when we have an anxiety attack our face temperature rises. These are some of the conclusions drawn in a pioneering study conducted at the University of Granada's Department of Experimental Psychology.
Apart from the temperature change and other signs on the person's face, it is also noted that the person who is lying will make extra efforts to establish the lie as a truth. He would repeat the same thing again and again. He might also say: Why would I lie to you? His emphasis on repeating: I am telling the truth, you can ask him or her, etc are useful signals to make him a suspect. The Pinocchio effect is a very useful way of observing people, through the changes in their body language and extra efforts they are making to convince the listener.