In this thesis, I shall focus on Doyle’s first Sherlock novel, A Study in Scarlet, as it introduces the characters and the protagonist’s methods of investigation in an especially detailed way. Furthermore, in this study I aim to shed light on the particular techniques of forensic science that Sherlock uses in his investigations and also his use of criminal psychology in identifying perpetrators. I would like to showcase that his methods not only move the plot forward and help solve mysteries, but they also make him a unique and groundbreaking detective character, who is ahead of his time. His observational skills, logic and evidence-based thinking is in contrast to the traditional criminal investigation techniques of the Victorian police, who often rely on superficial evidence and unreliable witnesses. By analyzing Holmes’ methods – such as fingerprint and footprint analysis or chemical experiments – I shall highlight how Doyle’s fictional detective predicts modern forensic practices and contributes to the evolution of crime literature.