Based on the example of murder committed by a 23-year-old man the authors express their disagreement with the term „uncontrollable affect“ which was used in the expert opinion led to an exculpatory conclusion because a pathic affect was involved and the second expert opinion mentioned only a simple and not very serious affect and the involved subject was able to differentiate and control his action. After a detailed analysis of the cause and development of fatal aggression the authors object to the term „uncontrollable affect“ and its confounding description of the legal and psychiatric psychological concept. The authors consider the already frequently criticized and refuted term „uncontrollable affect“ and the thus described conclusion which led to diminution of differentiating and control capacities inacceptable. In their opinion this description interferes in an inappropriate way with the competence and decision of the law court. Experts should only evaluate whether a given subject was or was not mentally ill and analyze from this aspect the motivation of his action. It is not up to experts to evaluate whether and how the offender controlled his mental processes.

        Key words: uncontrollable affect, offender, murder, motivational factors, mental processes.