Pleading Insanity for Criminal Defense



Insanity -- Prior Law


Before the adoption of the Insanity Defense Reform Act of 1984, most Federal courts various interpretations of the American Law Institute's Model Penal Code. This code specified that a person is not responsible for criminal conduct at the time such actions were taken as a result of mental illness or defect. This translates to the defendant claiming that they lack the mental capacity to understand criminal wrongdoing or the inability to conform to the requirements of the law. It is important to note that in this defense, the term “mental disease” or “mental defect” is not defined as a repeated criminal offense or other anti-social conduct. For example, a defendant and his or her counsel may not claim Insanity just because the defendant stole from the same store multiple times and got caught. The offense itself may not be used as a defense, but rather the defect or disease that is causing such behavior.


Present Statutory Test -- 18 U.S.C. § 17(A)

The Present Statutory Test was signed into law as a facet of the Insanity Defense Reform Act. This test applies toward applicable offenses committed after October 12, 1984 (the date that the Defense Reform Act was signed into law) and is codified as 18 U.S.C. § 17(a).


Affirmative Defense - An affirmative defense under any Federal statute would be that at the time that the criminal acts were committed, the defendant was unable to understand the nature and wrongfulness of his or her acts due to a severe mental illness. Otherwise, mental disease or defect does not suffice as a defense. The current standard entirely eliminates the cognitive/volitional test of the ALI Model Penal Code while also requiring that a mental disease or defect be severe. The facet of severity was added to emphasize that non-psychotic behavior disorders like an immature personality or a pattern of antisocial tendencies do not constitute as a valid defense. This standard was adopted and intended to incorporate case law that defines that the voluntary use of alcohol and drugs (even if they dull or eliminate the defendant's ability to understand the nature of his or her acts) does not give way for an insanity defense, but may provide for a “diminished capacity” under certain situations.


Under 18 U.S.C. § 17(b), the burden to prove an insanity defense by way of providing clear and convincing evidence lies entirely on the defense. Previous federal standards required the government to prove the defendant’s sanity beyond a reasonable doubt, but now, a defendant is automatically assumed sane until proven otherwise by himself or his legal counsel. This is also known as the Davis standard.


Scope of Expert Testimony

Federal Rule of Evidence 704 states:

Except as provided in subdivision (b), testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.

Expert witnesses testifying with respect to the mental state or condition of a defendant in a criminal case may not state their opinion or infer whether or not they believe a defendant lacked the mental capacity to be held responsible for the crime in which they were charged.


Rule 704 was amended in 1984 but before it was, mental health experts were permitted to state their opinions on whether or not a defendant met the relevant legal test for insanity. This amendment was intended to eliminate the confusing spectacle of multiple competing expert witness opinions. It is now intended that expert witness testimony is limited to presenting and explaining a defendant’s diagnosis and the characteristics of their disease or defect (if any). While a psychiatrist must be the one who provides expert testimony, it is the job of the legal factfinder to determine whether or not the standard for insanity has been met.


Special Verdict - “Not Guilty Only by Reason of Insanity” - Related Commitment Procedures at 18 U.S.C. §4243

If the issue of insanity is raised by notice of either party or the court (as prescribed in Rule 12.2 of the Federal Rules of Criminal procedure), the trier must find the defendant:

  • Guilty

  • Not Guilty

  • Not Guilty by Reason of Insanity


Section 4243 of Title 18 provides for a procedure of automatic commitment of individuals found not guilty by reason of insanity until they can establish the entitlement to release. These individuals are automatically committed pending a hearing which is to be held within 40 days of this finding to determine the person’s present mental state and danger they present to the public. A psychiatric or psychological exam plus a report must be completed before such hearing. Once the hearing commences, the burden of proof lies on the committed individual to prove that their release would not create a substantial risk of danger, or bodily harm to another person as a result of their mental disease or defect along with sufficient proof or evidence to back this claim. If the defendant fails to meet this burden of proof beyond reasonable doubt, the defendant will be placed with the State where the crime was committed by the Bureau of Prisons. Whether the State voluntarily accepts the inmate or whether the State requires Federal authorities to involuntarily commit the state into State custody, the State may not discharge the inmate until it has received a discharge order under 18 U.S.C. § 4243(f) from the Federal committing court.


Hospitalization of a Convicted Person Suffering from a Mental Disease or Defect -- 18 U.S.C. § 4244

Section 4244 of Title 18 prescribes an option for sentencing defendants who’ve been convicted and need care or treatment at a facility that is suitable for their mental defect or disease. After a hearing, the defendant who has been determined to be in need of a treatment facility will be committed to the custody of the Attorney General (for treatment). This commitment paves way for the maximum sentence term allowed for the convicted offense. If the defendant recovers from his or her defect or disease before this prescribed maximum term expires, the court will proceed to final sentencing and may modify the provisional sentence.


Hospitalization of a Person Due for Release but Suffering from Mental Disease/Defect -- 18.U.S.C. §4246

Section 4246 establishes a Federal commitment procedure for mentally ill individuals who are set to be released but whose release would pose a serious risk of bodily injury or property damage of others. This law is applicable to anyone who’s due for release because of the expiration of their sentence, the commitment to determine competency at trial has expired, or because charges have been dropped for reasons related to the mental condition of the individual. This statute is only to be used there are no other State authorities willing to accept a convicted individual for commitment.


Hospitalization of an Imprisoned Person Suffering from a Mental Disease or Defect -- 18 U.S.C. § 4245

Section 4245 of Title 18 gives a statutory right to a judicial hearing for all imprisoned Federal defendants who object their transfer to a psychiatric treatment facility. A hearing is not required before transfer for psychiatric evaluation, and the hearing on a longer-term transfer for treatment is generally held in the district of the Federal facility where the imprisoned individual has been sent for evaluation.


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