Is this patient not guilty by reason of insanity?
How to assess a defendant’s mental state at the time of the offense
Table 4
Irresistible impulse test for sanity: A modern interpretation
| Inability to defer the act |
| Inability to ignore specific instructions |
| Must not be caused by rage or intoxication |
| Magnitude, likelihood, and imminence of consequences if act is not performed |
| Attempted alternatives to the act |
| Genuineness of command hallucinations and the ability to ignore them |
Case continued: seeing red
When you interview Mr. B 3 months after his arrest, he is not psychotic. He says he ran out of his medications 6 months before he killed his wife and resumed taking them while in jail awaiting trial.
Mr. B relates that in the months before the offense he grew concerned that his wife was involved in “ritualistic sexual perversions” commanded by the devil. He tried to discuss this with his mother-in-law and minister but did not get a satisfactory response.
On the evening of the killing, Mr. B was particularly agitated while waiting for his wife to return home from work. She walked in wearing a red sweater, which indicated to him that she had had sex with 17 different men at work that day. To save her from eternal damnation for adultery, Mr. B believed he had to stab her 17 times before sunrise.
He becomes tearful during the interview and says he wishes he “could go back in time and fix things.”
Mr. B. shows clear evidence of a severe mental disease during the offense (psychosis, medication nonadherence) without a personality or substance use disorder.
Factors that indicate he did not know his actions were wrong at the time of the event include:
- his delusional belief that he was saving his wife from damnation
- lack of a rational motive
- lack of effort to conceal the offense
- his ready confession to 911 operators and police officers
- his cooperation with police.
Mr. B’s attempts at alternate solutions (discussions with clergy and his mother-in-law) and the perceived deadline (the need to kill his wife before sunrise to prevent damnation) indicate that he had an irresistible impulse.
Open to interpretation
As this case suggests, a defendant’s sanity or insanity is determined by many factors and is often open to interpretation. In court, the prosecution and defense aim to answer two complex questions:
- Did the defendant suffer from a mental illness? (This may be clear in patients with schizophrenia but more difficult to determine in others, such as in substance-induced mood disorder.)
- Did this mental illness alter the defendant’s judgment to such a degree that he or she no longer knew the offense was wrongful?
Recent cases. Despite her plea of not guilty by reason of insanity, Andrea Yates was convicted of murder in June 2002 for drowning her five children in the bathtub of their home. Though most would agree the Texas housewife suffered from a severe mental illness, prosecutors convinced the jury that she knew the wrongfulness of her actions. An appeal was granted earlier this year, and Yates returned to court in June.
Also this year, the U.S. Supreme Court heard a case contesting Arizona’s insanity defense on grounds that it violated a defendant’s right to due process. In late June, the court sided with the state, continuing to allow each to state to establish its own insanity defense standard.
Related resources
- American Academy of Psychiatry and the Law. www.aapl.org,
- Giorgi-Guarnieri D, Janofsky J, Keram E, et al. AAPL practice guideline for forensic psychiatric evaluation of defendants raising the insanity defense. J Am Acad Psychiatry Law 2002;30(2 suppl):S3-40.
- Noffsinger SG, Resnick PJ. Insanity defense evaluations. Directions in Psychiatry 1999;19:325-38.
