by Andrew Donohue, DO; Vinay Arya, MD; Lawrence Fitch, JD; and Debra Hammen, LCSW-C
Dr. Donohue is from Forensic Psychiatrist, Delaware Psychiatric Center, New Castle, Deleware; Dr. Arya is Attending Psychiatrist, Monmouth Medical Center, Long Branch, New Jersey; Dr. Fitch is Maryland Director of Forensic Services, Jessup, Maryland; and Ms. Hammen is Chief, Systems Operation, Maryland Office of Forensic Services, Jessup, Maryland.
Maryland’s test for a finding of legal insanity (not criminally responsible [NCR]) allows a defendant to be found legally insane due to either a lack of appreciation of wrongfulness (cognitive impairment [CI]) or lack of ability to refrain from illegal behavior (volitional impairment [VI]). During a four-year period, 1,446 defendants underwent in-depth (post screening) evaluations for the NCR plea at Maryland state hospitals. Of the 416 defendants assessed as NCR by the hospitals’ court-appointed evaluators, 44 (11%) were assessed as NCR due to VI alone. Diagnostically, the VI and CI groups were similar. Criminal charges were also similar, but the VI group was more likely to have been charged with murder. Many of the forensic evaluators concluded that the VI group was unable to refrain from illegal conduct based on considering a number of factors, including psychiatric symptoms and the defendant’s behavior as related to the offense. Some evaluators’ reports offered an opinion, but did not adequately explain what data they used to arrive at their conclusion. This paper examines the history of and rationale for a volitional test of insanity and how it is assessed by forensic evaluators.
insanity defense, not guilty by reason of insanity, irresistible impulse
The topic of volitional impairment (VI) in insanity evaluations has long been a subject of some controversy. Legal tests for insanity have changed over time and differ by jurisdiction. Whether to consider one’s ability to refrain from committing a crime or irresistible impulse, due to mental illness has been one of the primary exculpatory variables. The major reasons for differing views on whether VI should be taken into account when assessing insanity include difficulty in assessing and quantifying VI, difficulty in differentiating it from poorly planned or impulsive acts, and society’s hesitancy to excuse the types of offenses and psychiatric impairments that may lend themselves to a insanity defense due to VI alone.[1–3] Due to controversy surrounding the issue of whether VI should be included in consideration of legal insanity, the laws governing legal insanity differ greatly among states and have undergone substantial changes in many jurisdictions. Despite this, there is little data about the specifics regarding the application of this portion of the insanity defense and the criteria that evaluators use in evaluating these defendants and formulating an opinion on this issue.
The concept of irresistible impulse as a factor leading to an insanity finding has existed for a long time. In Parsons versus State (1886), a test of volition was proposed as an addition to the insanity rule of the time, the M’Naughten rule. At that time, it was believed that the M’Naughten rule failed to consider that while an insane defendant may not lose the ability to comprehend his actions and their wrongfulness, he might be unable to control his conduct. This case held that “Though conscious of [the nature of the act] and able to distinguish right from wrong, yet his will, the governing part of his mind, has otherwise been so completely destroyed that his actions are not subject to it, but are beyond his control.”
In the 1950s and 1960s, the American Law Institute developed its Model Penal Code. This included a recommendation for a test for insanity. The test included both cognitive and volitional parts and it was widely adopted.
After the assassination attempt on President Reagan and the insanity acquittal of his assailant, there was a public outcry against the insanity defense. Over 40 bills to abolish the insanity defense were introduced to Congress. The American Psychological Association, the American Psychiatric Association, and the American Bar Association provided public statements on the issue. The American Psychiatric Association supported eliminating the volitional prong to the insanity defense, stating, “The line between an irresistible impulse and an impulse not resisted is probably no sharper than that between twilight and dusk…The concept of volition is the subject of some disagreement among psychiatrists. Many psychiatrists therefore believe that psychiatric testimony (particularly that of a conclusory nature) about volition is more likely to produce confusion for jurors than is psychiatric testimony relevant to a defendant’s appreciation or understanding.”
The American Psychological Association recommended the review of existing literature as well as further research in order to determine whether “behavioral sciences are able to render informed opinions about behavioral control and whether such opinions assist the jury in making their scientific, moral and legal decisions regarding the defendant’s responsibility for the alleged acts.”
Decisions regarding culpability in the presence of a possible loss of volitional control remain controversial. Critics have asserted that because it is difficult to collect objective data about the extent of lack of control, VI can be easily feigned.[1,3] Opponents of a volitional test have argued, “Whatever the precise terms of the volitional test, the question is unanswerable—or can only be answered by ‘moral guesses’.” Furthermore, examples of psychiatric disorders that are thought of as having significant impulsive components include pyromania, kleptomania, paraphilias, and compulsive gambling. The courts and society as a whole appear not to wish to excuse the types of behaviors that result from these disorders,[9–12] likely because these disorders are often characterized by repeated illegal and dangerous acts, from which society is concerned with protection, rather than determination of culpability.
As a result of these criticisms, federal jurisdictions eliminated VI as a part of the defense[13–16] and many states followed suit. Federal and many state jurisdictions also prohibited psychiatrists from directly stating if it was their opinion that a defendant was legally insane, thereby reducing the conclusory nature of some psychiatric reports and testimony.
As of 2002, 16 states, including Maryland, have an insanity defense that allows defendants to qualify due to VI alone. Other states have incorporated a volitional test into determining if a defendant meets criteria for a different verdict, guilty but mentally ill. (Persons convicted as guilty but mentally ill receive the same criminal sanctions, including incarceration or death, as individuals who are simply found guilty, but they undergo an evaluation to determine if they require treatment within the department of mental health.) In Maryland, a defendant is not criminally responsible if “because of a mental disorder or mental retardation, [he] lacks substantial capacity to: 1) appreciate the criminality of that conduct; or 2) conform that conduct to the requirements of law.”
The manner by which VI contributes to criminal offenses was examined by Morse. He described two basic modes of loss of volitional control. The first involved compulsion resulting in illegal action in which the actor was driven by an irresistible force. The second involved the concept of a constrained choice, whereby “an actor is not physically forced to act, but circumstances produce a dreadfully hard choice that leaves the actor without a reasonable alternative.” For example, an individual experiencing a delusional belief that his neighbor’s satellite dish is causing him harm may believe that failing to destroy the satellite dish will result in serious injury. This individual may be fully aware that it is wrong to destroy others’ property, but believes that given the (delusionally) perceived threat, he has no alternative.
The American Psychiatric Association’s statement argued that volitional tests may be unnecessary because defendants who meet the exculpatory criteria set forth in a volitional test will usually meet the criteria for a cognitive impairment (CI) test as well. However, those in favor of preserving a volitional test maintain that debilitating but readily treatable psychiatric disorders, such as bipolar disorder, result in loss of volitional control, while cognitive knowledge and appreciation of wrongfulness/criminality remain intact. To ignore VI, particularly in the case of bipolar disorder, would lead to the conviction of “a class of psychotic patient whose illness is clearest in symptomatology, most likely biologic in origin, most eminently treatable, and potentially most disruptive in penal detention.”[21,22] As another example, in obsessive compulsive disorder, the possession of insight bears no relationship to an individual’s subjective sense of being able to control one’s behavior in performing compulsive acts. This underscores the potential for psychiatric illness to produce a loss of volitional control, while cognitive appreciation of wrongfulness is preserved.
In Maryland, insanity opinions were historically reached by the consensus of a board consisting of several psychiatrists. A retrospective study of their conclusions suggested that changing the criteria of the evaluations from an insanity test that included a volitional prong to one that did not would result in few changes in doctors’ opinions and would not reduce doctors’ disagreements about the ultimate issue.
Supporters of the volitional prong of the insanity defense contend that an irresistible impulse can be quantified. There is limited research, but some data to indicate that VI can be characterized with a structured interview that is focused on elaborating factors contributing to loss of volitional control. Due to concerns that the defense of insanity due to VI can be misused, the defense’s application has been limited.
Different states have developed their own strategies of accounting for VI in assigning criminal culpability among the mentally ill. Crimes due to extreme emotions have been specifically excluded in Virginia case law: “Frenzy arising solely from the passion of anger and jealousy, regardless of how furious, is not insanity.” Virginia law prevents irresistible impulse from being invoked in cases that involve any planning or preparation prior to the crime. An antiquated Pennsylvania law required that a defendant must have committed the exact same act previously in order to qualify for insanity due to VI.
It is clear that insanity (including cognitive, and depending on the jurisdiction, volitional prongs) is rarely brought forth as a defense and rarely contested in the United States, including Maryland.[28,29] Studies suggest that insanity due to VI makes up a small sample of all defendants evaluated by experts for the court as insane. The study by Warren, et al., of 617 defendants referred to court experts in Virginia for evaluation of legal insanity revealed that 47 were assessed as legally insane and only five (10%) of these were assessed as insane due to a volitional test alone. An unpublished study in Ohio revealed that 15 percent of NGRI conclusions by court psychiatric evaluators were based on the volitional test alone, before Ohio eliminated the volitional portion of its insanity test in 1990.
Despite all of the concern, pro and con, regarding the inclusion of VI in allowing a defendant to qualify for the insanity defense, there is little data about how frequently a defendant is assessed as or adjudicated insane by virtue of the volitional prong alone.
There is a body of literature and wealth of experience among prominent forensic practitioners available to guide the forensic examiner in considering relevant factors related to a defendant’s ability to refrain from an illegal act.[32,33] Despite this, there is little data available when examining the factors that evaluators consider in formulating an opinion regarding a defendant’s ability to refrain from an illegal act. Furthermore, the American Psychiatric Association’s statement on the insanity defense professes the need to avoid psychiatric opinions of a conclusory nature, and suggests that these opinions are unduly common in the assessment of volitional capacity.
The current study was designed to quantify the proportion of assessments of legal insanity that are attributable to VI alone, to explore the differences between the volitionally impaired and cognitively impaired groups, and to examine how evaluators conceptualized cases in which they assessed a defendant as incapable of refraining from criminal behavior.
This study was approved by the Institutional Review Board of the state of Maryland. In Maryland, the court orders forensic screeners (either a psychiatrist or a psychologist) to evaluate a defendant for the not criminally responsible (NCR) defense. If the forensic screener believes that the defendant is possibly NCR, then the examinee is referred for a more in-depth evaluation at one of Maryland’s state hospitals. Defendants with more serious charges are referred to the state’s only maximum security hospital, Clifton T. Perkins Hospital.
The in-depth forensic evaluation either occurs in an inpatient or outpatient setting, depending on which facility is utilized and whether the defendant has other active psycholegal issues (e.g., the defendant is assessed as incompetent to stand trial and admitted for competency restoration). The evaluator is either a psychiatrist or psychologist with training in forensic evaluations. If trainees are utilized, they are supervised by a forensically trained supervisor.
We reviewed the evaluators’ opinions regarding criminal responsibility to determine which portion of the insanity test was used to assess the defendant as (NCR). Defendants evaluated as NCR because they lacked substantial capacity to conform their conduct to the requirements of the law only (VI group), were separated from those who were assessed as NCR because they lacked substantial capacity to appreciate the criminality of their conduct and those that both lacked substantial capacity to appreciate and conform (CI group). We then compared the demographic information, additional background data, nature of the offenses, and diagnoses of the VI group to all others assessed as NCR (CI only and the CI + VI groups).
Two of the authors further examined the VI group by reviewing reports to determine which factors evaluators relied upon in determining if a defendant lacked substantial capacity to conform his conduct to the requirements of the law (or were volitionally impaired). Usually, the forensic evaluator cited a main factor that led to a defendant being assessed volitionally impaired; this factor was recorded. Additionally, we reviewed reports to determine which other factors identified in forensic literature and by leading forensic experts were examined and commented upon in the evaluator’s report in support of the evaluator’s opinion that the defendant was volitionally impaired at the time of the offense. These factors included symptoms of disorganization, hallucinations, command hallucinations, delusions and mania. Other factors were deferability (i.e., the ability to refrain from acting for a period of time) perceived negative consequences for failing to act, perceived alternatives, evidence of planning, and hypothetical tests of volitional ability (such as the policeman at the elbow test, in which the evaluator poses questions to determine if a defendant would have committed the same offense in the presence of a police officer, or despite the likelihood of immediate apprehension).
We reviewed forensic mental health evaluations for all individuals assessed as not criminally responsible in Maryland during fiscal years 2002 to 2005. Data collected included demographic information (age, race, sex, marital status, and educational level), additional background data (the examinee’s history of outpatient or inpatient psychiatric treatment and history of arrest), psychiatric diagnoses and the nature of the offense for which the defendant was being evaluated. These data were formally provided by the forensic evaluator in a checklist, completed with the forensic report. Values representing the proportion of those found NCR by the volitional prong only versus those found NCR by the cognitive prong were formally compared using the Fisher’s exact test. A comparison of the mean age could not be made because the standard deviation for each group was not available.
A total of 1,446 defendants underwent an in-depth evaluation for the insanity defense at a Maryland state hospital during fiscal years 2002 to 2005. Of these, 416 (29%) were assessed as NCR by the hospitals’ court appointed evaluators. 44 of the 416 defendants assessed as NCR (11%) were assessed as NCR due to VI alone while 372 (89%) were assessed as NCR due to CI. Of the 372 individuals assessed as NCR due to CI, 361 of them were assessed as NCR based on CI + VI, while only 11 were assessed as being cognitively but not volitionally impaired (CI only). Because the focus of this paper was to examine the role of VI , and because a relatively small number of individuals met criteria for CI only, the comparison group was made to include all individuals with CI (CI only and CI + VI).
There were few statistically significant differences between the group of defendants assessed as NCR due to VI when compared to the CI group across most variables. The VI group was more likely to be widowed, but aside from this, there were no significant differences in the demographics or background data. These findings are summarized in Table 1.
The VI group was more likely to be charged with murder. Furthermore, The VI group was significantly more likely to be involved in driving while intoxicated or drug-related offenses. The CI group was more likely to have been charged with minor offenses. These findings are summarized in Table 2.
There were no significant differences between the VI and CI groups with regard to psychiatric diagnoses. Psychotic disorders represented the most common diagnoses, with 62 percent (229) of the CI group and 57 percent (25) of the VI group falling into these categories. Schizophrenia was the most common diagnosis, comprising 31 percent of the CI group and 32 percent of the VI group. Mood disorders made up 32 percent from both the CI and VI groups. Twenty-three percent of the CI group and 21 percent of the VI group were diagnosed with bipolar disorder. Defendants with bipolar disorder in the VI group all were in the midst of a manic state at the time of their offense, while data regarding the proportion of manic verses depressed persons in the CI group were unavailable.
More controversial diagnoses were present, but uncommon in the VI group. For example, only 1.9 percent (7) of the CI group fell into the category “other disorders that may affect impulse control,” while four percent (2) of the VI group fell into this category. Of these two cases in the VI group, one was diagnosed with a personality disorder and one was diagnosed with personality change due to a medical condition. The results are summarized in Table 3.
Typically, the court-ordered evaluator commented in his or her report that a particular factor was the main reason that the defendant lacked the ability to conform his or her conduct to the requirements of the law. Sometimes evaluators identified more than one main factor. These results are summarized in Table 4. Examples included poor impulse control, disinhibition, and various types of delusions. Delusional beliefs were most commonly cited by the evaluator as the main factor connecting the defendant’s mental illness to the offense, representing 18 of 44 samples or 37 percent of the total. In these cases, evaluators suggested that a defendant’s actions were (mis)guided by delusional beliefs. A defendant may have acted violently in the presence of what he perceived to be a threat, based on a delusional belief system. Poor impulse control was the second most commonly cited factor at 14 percent. These cases often involved defendants who were demonstrating significant symptoms of mental illness and were noted to be impulsive, both in regard to the offense and at other times. Mania was the main factor in 10 percent of cases. These defendants usually engaged in reckless and impulsive behavior, while in the midst of a manic episode. Command hallucinations were the main factor in 8.2 percent of cases. These cases involved individuals who had difficulty refraining from their offense because they were experiencing hallucinations telling them to commit the crime in question.
Evaluators documented an average of 2.9 out of the 10 factors relevant to assessing a defendants’ ability to conform their conduct to the requirements of the law. The standard deviation was 1.9. Evaluators most often commented about a defendant’s symptoms, such as delusions, 64 percent (28) of the time. Other symptoms mentioned included mania 41 percent (18), hallucinations 39 percent (17), disoganization 32 percent (14), and command hallucinations 16 percent (7). Other factors considered were documented less often as relevant to the evaluators’ opinion than symptoms. These factors included evidence of planning 41 percent (18), concern for consequences of failing to act 39 percent (17), ability to defer acting for a period of time (deferability) 11 percent (5), consideration of alternatives nine percent (4), and hypothetical explorations two percent (1) (Table 5).
These results indicate that a relatively small percentage (11%) of defendants assessed by court appointed forensic evaluators as NCR meet criteria for a volitional test, while not meeting criteria for a cognitive test.
The VI group was more likely to be accused of murder or a drug-related offense and the CI group was more likely to have been accused of a minor offense. The reasons for these differences are unknown, but possibly could be related to the fact that violent offenses, such as murder and drug-related offenses (driving while intoxicated, possession or delivery of drugs) are often impulsive or reactive in nature, and perhaps more likely to occur in individuals who are disinhibited or excessively driven, such as manic individuals or persons with frontal lobe brain injuries. Aside from this, those assessed as NCR due to VI alone did not differ from the defendants assessed as NCR due to CIs in any substantial way.
Both groups had similar psychiatric diagnoses; serious psychiatric disorders, such as schizophrenia, bipolar disorder and schizoaffective disorder, were the most common diagnoses. Less severe psychiatric illnesses were slightly more common in the VI group, but this did not represent a statistically significant difference.
These data suggest that many of the concerns about having an insanity test, which allows for a defendant to be found legally insane due to VI or irresistible impulse, may have been overstated. Because a small, but relevant percentage of all defendants who were evaluated as NCR met this criteria due to a volitional test alone, one might conclude that a volitional test is relevant and not overused.
Defendants assessed as NCR due to VI are as likely to have a major mental illness as defendants assessed as NCR due to CI. As evidence of this, the top four items cited as main factors contributing to loss of volitional control were delusions, poor impulse control, mania, and command hallucinations; these items represent symptoms that are associated with serious mental illness. As additional evidence, the individuals who were assessed as NCR due to VI had similar rates of serious psychiatric illnesses when compared to the CI group. Psychotic illnesses were the most common diagnoses in both the CI (61.5%) and VI (56.8%) groups.
Criticisms of tests of volition, including the criticism of the American Psychiatric Association, have suggested that evaluators’ opinions regarding VI are too often conclusory. In this study, evaluators documented an average of 2.9 out of 10 factors relevant to assessing VI. This result was consistent with the overly conclusory manner critics have eschewed. Evaluators more often commented on factors related to psychiatric symptoms, such as the presence of delusions, mania, or hallucinations, rather than other factors, but certain nonclinical factors, such as evidence of planning and consideration of consequences for failing to act, were often addressed. The standard deviation of 1.9 suggests that some evaluators documented many factors relevant to VI and explained these in arriving at their opinion, while others did not explain their reasoning in their report. This is consistent with the critics’ notion that evaluators must continue to strive to explain their opinions rather than provide conclusory statements.
The primary outcome measure in this study is the opinion of court-appointed forensic evaluators and not the actual court outcomes of these cases. These results cannot be generalized unless one assumes that this sample from Maryland is representative of defendants from all states with an insanity test that allows for VI. Furthermore, it is important to note that certain selection factors are relevant. In Maryland, Clifton T. Perkins Hospital performs forensic evaluations on individuals with more serious charges and this is also a primary training site for two forensic psychiatry fellowships. Therefore, individuals with more serious charges are more likely to be evaluated by a forensic psychiatrist-in-training, supervised by a board-certified forensic psychiatrist, and in an academic environment.
In conclusion, a minority of defendants assessed as NCR lack the ability to refrain, while they possess a cognitive understanding of wrongfulness, and this small percentage of defendants do not differ diagnostically from those assessed as legally insane when a cognitive test of insanity is applied. While there are established factors noteworthy in considering VI, evaluators often do not examine these in a systematized way. These findings suggest that forensic evaluators would meet the majority of the present critics’ recommendations more closely by giving less conclusions and more reasons.
Most states do not allow for VI in the consideration of legal insanity. This study suggests that to fail to account for VI in the application of the insanity defense may be a mistake for several reasons. First, persons assessed as insane due to VI have serious psychiatric diagnoses, consisting primarily of psychotic disorders. Second, their criminal charges are generally similar to others assessed as NGRI. Third, and perhaps most importantly, this group represents a small but relevant number of individuals who qualify for the insanity defense (according to court-appointed examiners). To neglect the issue of VI in considering legal insanity would result in the unavailability of this defense for a relevant group of individuals with major mental illnesses who were experiencing active and measurable symptoms related to their (alleged) offense.
This study’s exploration of the subject of the inability to refrain offers some insight into evaluators’ perspectives on this issue. Further questions remain; for example, how to quantify irresistible impulse, what are the actual legal outcomes to these cases and how do juries approach such cases. The task as set forth by the American Psychological Association’s position on the insanity defense was to conduct additional research to shed light upon the issue of VI as a part of the insanity defense. Clearly, further research is necessary to greater understand this complex issue.
1. Bonnie RJ. The moral basis of the insanity defense. Am Bar Assoc J 1983;69:194–7.
2. Denno DW. A mind to blame: New views on involuntary acts. Behav Sci Law 2003;21:601–18.
3. Melton GB, Patrila J, Poythress NG, Slobogin C. Psychological Evaluations for the Courts: A Handbook for Mental Health Professionals and Lawyers, Second Edition. New York, NY: Guilford Press, 1997.
4. Parsons v State, 81 Ala. 577,596, 2 So. 854, 866 (1886)
5. ALI Model Penal Code, § 4.01(1985)
6. American Bar Association. Standing Committee on Association Standards for Criminal Justice. Criminal Justice and Mental Health Standards. Chicago, IL: American Bar Association, 1984.
7. American Psychiatric Association. Insanity Defense Work Group. Statement on the insanity defense. Am J Psychiatry 1983;140:(6);681–8.
8. American Psychological Association. Text of position on the insanity defense. APA Monitor 1984;15:11.
9. U.S. v. Lewellyn, 723 F.2d 615, 618-20 (8th Cir. 1983)
10. U.S. v. Gould, 731 F.2d 45, 50-52 (4th Cir. 1984)
11. State v. Lowitzki, 285 Ill. 3d 770; 674 N.E. 2d 859 (1996) appeal denied 172 Ill. 2d 560, 679 N.E.2d 383 (1997)
12. U.S. v. Torniero, 735 F.2d 725, 50-52 (2nd Cir. 1984) cert. denied, 469 U.S. 1110 (1985)
13. Pub. L. No. 98–474, 98 Stat. 2057 (1984)
14. United States v. Lyons, 731 F.2d 243, 248 (5th Cir.1984), cert denied, 105 S. Ct. (1984)
15. Mossman, D. United States v. Lyons: Toward a new conception of legal insanity. Bull Am Acad Psychiatry Law 1988;16(1):49–58.
16. Callahan L, Mayer C, Steadman HJ. Insanity defense reform in the United States: Post Hinkley. Mental Physical Disabil L Rep 1987;2:54–9.
17. Giorgi-Guarnieri D, Janofsky J, Keram E, et al. Practice guideline: Forensic psychiatric evaluation of defendants raising the insanity defense. Am Acad Psychiatry Law 2002;30(2 Suppl):S3–40.
18. Pamer CA, Hazelrigg M. The guilty but mentally ill verdict: A review and conceptual analysis of intent and impact. J Am Acad Psychiatry Law 2000;28(1):47–54.
19. CP § 3-109, Annotated Code of Maryland.
20. Morse, SJ. Causation, compulsion, and involuntariness. Bull Am Acad Psychiatry Law 1994;22(2):159–80.
21. Silver SB. Dissection of the prongs of ALI: A retrospective assesment of criminal responsibility by the psychiatric staff of Clifton T. Perkins Hospital Center. Bull Am Acad Psychiatry Law 1983;11(4):383–91.
22. Simon R, Aaronson DE. Governor’s task force to review the defense of insanity, state of Maryland, reported. In: Callahan L, Mayer C, Steadman HJ (eds). The Insanity Defense A Critical Assessment of Law and Policy in the Post-Hinckley Era. New York, NY: Praeger Publishers, 1988.
23. Rotter M. The relationship between insight and control in obsessive-compulsive disorder: Implications for the insanity defense. Bull Am Acad Psychiatry Law 1993;21(2):245–52.
24. Rogers R. APA’s Position on the Insanity Defense: Empiricism v. Emotionalism. Am Psychologist 1987;42(9):840–8.
25. Thompson v Commonwealth, 193 Va. 704, 717, 70 S.E. 2d 284, 291-92 (1952)
26. Commonwealth v. Mosler, 4 Pa. 264 (1846). In: Melton GB, Patrila J, Poythress NG, Slobogin C. Psychological Evaluations for the Courts: A Handbook for Mental Health Professionals and Lawyers, Second Edition. New York, NY: Guilford Press, 1997.
27. Cirincione C, Steadman HJ, McGreevy MA. Rates of insanity acquittals and the factors associated with successful insanity pleas. Bull Am Acad Psychiatry Law 1995;23(3):399–409.
28. Janofsky JS, Dunn MH, Roskes EJ, et al. Insanity defense pleas in Baltimore City: An analysis of outcome. Am J Psychiatry 1996;153(11):1464–8.
29. Janofsky JS, Vandewalle MB, Rappeport JR. Defendants pleading insanity: An analysis of outcome. Bull Am Acad Psychiatry Law 1989;17(2):203–11.
30. Warren JI, Fitch WL, Dietz PE, Rosenfled BD. Criminal offense, psychiatric diagnosis, and psycholegal opinion: An analysis of 894 pretrial referrals. Bull Am Acad Psychiatry Law 1991;19(1):63–9.
31. Resnick PJ. Personal communication. September 26, 2006
32. Noffsinger SG, Resnick PJ. Insanity defense evaluations. Directions in Psychiatry 1999;19:325–38.
33. Rodgers R, Shuman D. Conducting Insanity Evaluations, Second Edition. New York, NY: Guilford Press, 2000.