In the beginning of the 20th century the first scientific papers on methods on lie detection emerged. The psychologist William Stern (1871-1938) conducted research on human intelligence and individuality contributed to this research. The Psychology professor Udo Undeutsch presented the Undeutsch hypotesis in the mid fifties and later became the foundation for Criteria Based Content Analysis (CBCA). The Swedish professor in Pedagogy and Pedagogy psychology Arne Trankell (1919-1984), wrote several books about witness psychology. The methods used is based upon that the person tells the story differently, if it is self-experienced or made up. It is the small differences in the story that may reveal if the story is true or not.

Security Manager use two methods, one method is called Multiple Suspect Elimination and is suitable if there is a large number of suspects. The method is used to speed up the investigations, by quickly identify the truthful persons from the deceptive, who seem to withhold information or lying. A number of direct questions that triggers certain behavior are asked. The answers are analyzed and the truthful people can be separated from the deceptive, and the investigation can proceed quicker. This method can be used to analyze both verbal and written statements.

The other method is used to analyze a statement written by the suspect. It takes longer time to conduct the analysis and is suitable when there is a few number of suspects. The method analyzes the story and reveals clues on what parts in statement that is more likely to be deceptive. The method is used to analyze letters, witness statements and transcribed interviews.

Klas Nilsson who is a Professional Certified Investigator (PCI) and Certified Fraud Examiner (CFE), has studied Criminology, Text Analysis, Content Analysis, Interview and Interrogation Techniques and Detecting Deception in Verbal and Written Statements in USA.