Abstract
This study illustrates the impact on forensic psychiatric investigations (FPI) of time-specific scientific theories and moral normative considerations. A comparative historical perspective illustrates historical FPI procedures (i.e. methodology and focus), based on two matched FPI case reports from the 1930s: a man and a woman who had shot their respective spouses. First, in the analysis, a comparison was made between the two cases regarding assessment procedure and focus, applying a gender perspective, and second, stability and change in FPI praxis between the 1930s and the 2020s were identified. Similarities and differences were discussed based on changes in FPI praxis and influence of explanatory models within psychiatry. This can aid understanding of historical bias and indicate current bias and its risks to FPI reliability.