§ 344.3. Rules of evidence; psychiatric testimony in certain cases.
When, in connection with a defense of mental disease or defect, a
psychiatrist or licensed psychologist who has examined the respondent
testifies at the fact-finding hearing concerning the respondent's mental
condition at the time of the conduct charged to constitute a crime, he
must be permitted to make a statement as to the nature of the
examination, the diagnosis of the mental condition of the respondent and
his opinion as to the extent, if any, to which the capacity of the
respondent to know or appreciate the nature and consequences of such
conduct, or its wrongfulness, was impaired as a result of mental disease
or defect at that time. The psychiatrist must be permitted to make any
explanation reasonably serving to clarify his diagnosis and opinion, and
may be cross-examined as to any matter bearing on his competency or
credibility or the validity of his diagnosis or opinion.