The monograph deals with the current topic of legal and professional aspects of expert work, including process management and the quality of forensic procedures. He mentions the new law on experts, effective from January 1, 2021, and emphasizes that an expert opinion, often used especially in court and sometimes administrative proceedings, is not a binding tool for a legal solution. An expert opinion is used to obtain expertly based information relevant to the proceedings and, if performed correctly, can be key evidence for clarifying the subject of the dispute. Despite their non-binding nature, the conclusions of expert opinions can differ significantly, which can lead to a court decision on the need for further investigation. The authors further elaborate the relationship of forensic sciences to the current scientific system, their use in the process of proof and legal definitions. Forensic science is described as a key element in developed legal systems that enables the objective analysis of evidence and supports both the investigation and the defense. The publication points to the essential role of standardization and quality of forensic work, draws attention to shortcomings in the quality control system and suggests the need for improvement to make justice more efficient and fair