LEGAL PRINCIPLE: CRIMINAL LAW – Defence of Insanity – Expert Psychiatric Opinion May Be Based on Observations and Third-Party Information
PRINCIPLE STATEMENT
A psychiatrist may form expert opinion based on information from nurses, patient's relatives, personal observations, and interpretation of proceedings records.
RATIO DECIDENDI (SOURCE)
"I formed my opinion based on the information given to me by my nurse, relations of the patient as well as my observations and also by my interpretation for the record of proceedings."
EXPLANATION / SCOPE
Psychiatric experts need not personally observe all relevant behavior to form opinions. They may rely on multiple information sources: medical records, nursing staff observations, family member accounts of behavior, and their own examinations. This reflects psychiatric practice where diagnosis involves collating various evidence sources. The expert must explain the basis for their opinion, allowing courts to assess its weight. Information from third parties (nurses, relatives) isn’t hearsay when used to explain expert opinion basis—it’s admissible to show the foundation of expert conclusions. However, courts assess whether reliance on such information was reasonable and whether the expert’s conclusions are soundly based. This principle enables realistic psychiatric assessment while maintaining evidentiary standards