Society owes a commitment to its people and citizens that the strength of the states is not abused during the dispensation of justice and human rights are upheld at all times. To preserve rights, the most basic tool used by humans is the police set-up. More often than not, third degree methods are used to extract information to get further in the investigation. However, this completely defeats the purpose of human rights that we so greatly pride ourselves on. In order to overcome this problem, in the criminal justice system, there are lie detector tests that can be used. These tests are of three types- Polygraph, Narcoanalysis, Brain-Mapping (BEAP). Each of these tests uses a different mechanism to evaluate different aspects of the human body to tell dishonesty from honesty. Lie detector tests have been particularly helpful as they help in limiting or eradicating third degree methods in investigations and protecting the human rights of all citizens. Unfortunately, these tests have not managed to garner too much support due to certain technical issues and admissibility problems but researchers and scholars have ascertained a 95-98% success rate of these tests. This paper seeks to analyse the use of lie detectors in criminal law.