In certain cases, New Jersey recognizes that a defendant may not be legally responsible for their actions if they were suffering from a severe mental disorder when they committed a crime. If successful, it can mean the difference between incarceration and receiving necessary psychiatric treatment. Although it’s often dramatized in movies and television, the insanity defense is rarely used, and it’s a tough threshold to meet.
Defining the Insanity Defense
Under N.J.S.A. 2C:4-1, someone may use the insanity defense if they were suffering from a “mental disease or defect” when they committed a crime. However, they must have been so impaired by the mental illness that they either:
- Didn’t understand what they were doing, or
- Didn’t know that what they were doing was wrong
“Mental disease or defect” isn’t a medical diagnosis – it’s a legal standard. The term “insanity” isn’t used by mental health professionals, either. “Insanity” and “mental disease or defect” are defined by the courts.
With a successful insanity defense, a defendant may be found not guilty by reason of insanity. This means they are not criminally responsible for the offense. However, they aren’t automatically released or put in a mental health facility indefinitely. Instead, there will be further proceedings to determine the appropriate restrictions for the defendant.
How to Prove “Insanity”
The burden of proving legal insanity rests entirely on the defense. The defendant must show by a preponderance of the evidence (more likely than not) that they met the legal standard for insanity at the time of the offense. This is a lower threshold than beyond a reasonable doubt, but it still requires persuasive evidence. The courts have ruled that expert opinion testimony is required to meet the standard of proof.
Typically, a defense team will use expert testimony from qualified psychiatrists or psychologists who have evaluated the defendant. They first determine whether the defendant was suffering from a significant mental disease or defect. Next, they assess whether it impaired the defendant’s ability to understand their actions or right from wrong.
Medical records and a history of mental illness, including prior diagnoses or involuntary psychiatric commitments, can support the insanity defense. Witness testimony from family members, friends, or law enforcement officers can also provide valuable context. These people can often testify about the defendant’s behavior before, during, and after the alleged crime.
Conditions That Fall Under “Mental Disease or Defect”
Not every mental health diagnosis meets the legal standard required under New Jersey law. Some of the mental conditions commonly associated with successful insanity defenses include:
- Schizophrenia
- Bipolar disorder with psychotic features
- Delusional disorder
- Severe post-traumatic stress disorder (PTSD) involving dissociative episodes
- Some forms of brain damage or cognitive impairment
These illnesses are often accompanied by hallucinations, delusions, dissociation, or significant cognitive dysfunction. However, this list isn’t exhaustive. Other severe mental illnesses or conditions may support a defense of insanity. The key is proving the defendant’s impairment at the time of the crime. A diagnosis alone is not enough to meet the defense’s burden.
Conditions like depression, generalized anxiety disorder, or personality disorders generally do not meet the threshold for an insanity defense unless the symptoms are extraordinarily severe and disabling.
One example of a successful insanity defense is the Cody Metzker-Madsen case. In this case, Metzker-Madsen killed his five-year-old foster brother while the two were playing alone outdoors. The defendant testified that he was in his “own world” at the time of the murder. He believed his brother “was a goblin commander that he needed to kill.”
Another famous example is the Andrea Yates case, where a mother suffering from severe postpartum depression, postpartum psychosis, and schizophrenia drowned her five children in the bathtub.
Both of these defenses were supported by significant evidence and expert testimony. They showed that even though the defendants might be competent to stand trial now, they didn’t understand their behavior or that it was wrong.
Insanity vs. Incompetence to Proceed
The insanity defense is often confused with incompetence to stand trial. However, these are separate legal issues:
- Insanity – The insanity plea defense focuses on the defendant’s mental state at the time of the alleged crime. It asks whether a mental illness prevented the person from understanding what they were doing or that it was wrong.
- Incompetence – In contrast, incompetence to proceed refers to the defendant’s current ability to understand the legal process and participate meaningfully in their own defense. In other words, the defendant doesn’t understand the charges against them, the legal system, or how to assist their attorney.
Incompetence findings are safeguards to make sure that a defendant receives a fair trial. If a person is found incompetent, the court may pause the proceedings until their competence is restored (often through mental health treatment).
A defendant can be deemed competent to stand trial yet still raise an insanity defense. For example, someone with schizophrenia may now appear stable and able to follow court proceedings because they are receiving effective treatment. However, if they were experiencing a psychotic episode when the crime occurred, they may still have a valid insanity defense.
If incompetence or insanity are an issue in your or a loved one’s case, working with an experienced criminal defense attorney is critical. Because the insanity threshold is so difficult to meet, insanity defense cases require significantly more resources and a stronger legal strategy than many other defenses.
Call Our New Jersey Criminal Defense Attorneys for Help with Your Case
If you or a loved one is facing criminal charges and believe mental illness played a role, call the Law Offices of Jonathan F. Marshall. The insanity defense is highly technical and fact-specific. It must be backed by expert testimony and detailed evidence to be deployed effectively.
At the Law Offices of Jonathan F. Marshall, our team offers over 200 years of combined experience handling criminal cases across New Jersey. We understand what it takes to present a strong and credible claim. One client said our services “provided [them] with both comfort and confidence.” Our results speak for themselves, including dismissed charges, reduced penalties, and favorable outcomes in serious felony cases.
To discuss your situation and explore your legal options, contact our New Jersey criminal defense attorneys today.
