Criminal behavior is frequently labeled mental illness just because it represents deviation from the norm, and the offenders' free will over their behavior is thus denied. At the same time, labeling is dependent on whether psychiatrists have institutional space available to treat the individual offenders. To determine mental competence, experts must ascertain the degree of reduced personal freedom on the basis of the seriousness of psychological deficiencies. This is accomplished by evaluating offenders' own statements about voluntary decisions, behavior before offenses, previous law-abiding behavior, and capacity for such an offense. Unfortunately, this process lends legitimacy to psychiatric norms without really measuring offenders' capacity of self-determination. Historically, psychiatrists have found in criminal justice a new field for expanding their power. In the arrangement which has evolved between psychiatry and justice, offenders are deemed incompetent due to abnormal psychopathy. As they are abnormal but not 'sick,' psychopaths can be found guilty but saved from severe penalties by declarations of reduced mental competence, a paradoxical compromise. In this system, criminal psychiatrists are implicit moralistic legitimators of punishment while explicitly using a 'scientific' jargon. At the basis of these psychiatric concepts are the premise of human autonomy and a three-level model for human behavior, which considers intellect of primary importance, followed by will and needs. The division of responsibilities between psychiatric experts and judges remains unclear: on one hand, the psychiatrist must decide under what conditions mental incompetence may be considered a factor at the time of a crime; on the other, judges, not experts, must make the final decision on competence. The essence of the problem is that criminal psychology has assumed the role of trying to support existing criminal policy with scientific arguments. Notes and a bibliography are supplied. --in German.