Forensic linguistics is a branch of applied linguistics which deals with the analysis of linguistic evidence to clarify the ambiguities existing in any judicial process, especially in investigation crimes and legal issues. This field investigates legally valuable texts and linguistic evidence such as handwritten texts prior to a suicide, documents and evidence remained from a crime scene and notes of abductors. Discourse analysis is also widely carried out with the following aims to: understand the identity of the writer; identify the speaker with reference to the recording; and provide expert reports for legal authorities and police. The analysis of discourse greatly assists judicial system personnel to find truth. It is necessary for police officers, security experts and judges working in courts to become familiar with the potentials and application of forensics linguistics and its role in the success of legal investigations in order to attain truth in judicial processes.