The Not Guilty by Reason of Insanity (NGRI) Defense in Missouri is a legal argument used by the defense in criminal cases someone charged with a crime argues that, due to a mental illness, they couldn’t fully understand their actions at the time of the alleged crime occurred. While this defense doesn’t completely let them off the hook, it can lead to a different outcome—like going to a hospital for mental health treatment instead of serving time in jail or prison.
From the state’s point of view, the criminal justice system is usually about punishing those who break the law. But, thanks to the U.S. Constitution, everyone has the right to a fair trial. The use of a “not guilty by reason of insanity” plea allows the court to assess a defendant’s mental health before declaring them guilty or handing down a sentence.
What Is the Not Guilty By Reason of Insanity Defense in Missouri?
Most defenses in Missouri criminal cases aim to either:
- Prove, or at least cast doubt in the jury’s mind, that the facts the state presents aren’t accurate (for example, the defendant had an alibi, acted in self-defense, or was present but not involved in the crime); or
- Show that the state did not meet its burden of proof to establish the defendant’s guilt beyond a reasonable doubt.
However, when pleading not guilty by reason of insanity, your defense attorney isn’t necessarily challenging the facts of the case or the prosecution’s evidence. Missouri’s not guilty by reason of insanity plea is based on the M’naghten Rule, which means the defense has to prove one of two things:
- The defendant didn’t know what they were doing when they committed the act; or
- That they knew what they were doing, but didn’t know it was wrong
Missouri Revised Statute §552.030 details the eligibility for and process of pleading not guilty by reason of insanity:
- A person who committed a crime cannot be held legally responsible if a “mental disease or defect” prevented them from understanding the “nature, quality, or wrongfulness” of their actions.
- To use a defense based on mental illness, the defendant must officially state this when they enter their plea or within ten days of pleading not guilty. This doesn’t prevent them from using other defenses as well.
- If the defendant uses this defense, the court will order a mental health evaluation by professionals. The evaluation report will be kept private and shared with the court and attorneys.
- If the report suggests that the defendant should be in a hospital before the trial, the court may order them to stay in one unless they’re released on bail or other conditions.
- Anything the defendant says during their mental health evaluation cannot be used against them to prove they committed the crime. It can only be used to assess their mental state.
- While everyone is “presumed innocent” before they’re convicted, the defense has to prove the mental illness affected the defendant during the crime. Otherwise, the court will assume the defendant did understand their actions at the time.
- If a defendant is found not guilty due to mental illness, the court will state this clearly in the verdict, along with the specific crime they were acquitted of.
At the trial, it is up to the jury to decide whether or not the defense has proven that the defendant was not guilty by reason of insanity.
Missouri Revised Statute §552.040 explains what happens next:
- If someone is found not guilty due to a mental disease or defect, they will be committed to the Missouri Department of Mental Health for care.
- If the crime was not a “dangerous felony” (like violent crimes), murder in the first degree, or sexual assault, the court might consider an immediate release under specific conditions if a professional mental health evaluation recommends it.
- If someone is not released, they must remain in a “secure facility” (meaning, they cannot leave or move freely without permission or supervision).
- If someone wants to be released from a mental health facility, they or the facility’s head can apply to the court for conditional or unconditional release. A hearing will be held to decide whether the person can be safely released. They need to show they no longer pose a danger due to their mental condition.
- During hearings for release, the court looks at factors such as the person’s current mental health, behavior in the facility, the nature of their crime, and the time since their last dangerous act.
- If someone on conditional release violates the conditions, the Department of Mental Health can revoke the release and return the person to the facility.
Common Reasons for Pleading Not Guilty By Reason of Insanity in Missouri
Every defense strategy in criminal cases in Missouri is based on the specifics of the case. Common reasons one may plead not guilty by reason of insanity include:
- Schizophrenia or Paranoid Delusions: Defendants may claim they were unable to distinguish reality due to delusions or hallucinations (for example, believing someone is “after them”), impairing their ability to understand the wrongfulness of their actions.
- Severe Bipolar Disorder: During extreme manic or depressive episodes, individuals may lose control over their actions, leading to irrational or violent behavior without understanding the consequences.
- Dissociative Disorders: Defendants may argue they had a dissociative episode, causing a loss of awareness, memory, or identity at the time of the crime.
- Major Depressive Disorder with Psychosis: In extreme cases, individuals may experience psychosis during deep depressive states, causing them to act violently or irrationally without understanding their actions.
It’s important to note, just having a mental illness doesn’t mean you’re automatically not guilty; you must show how that illness affected you during the commission of the crime.
You Need a Skilled Missouri Criminal Defense Attorney to Win a NGRI Case
The not guilty by reason of insanity defense is notoriously difficult to prove. Only .85% of criminal defendants use the defense, and only .26% of those are successful (nationally, about 30 cases a year).
Successfully using the NGRI defense involves navigating complex laws, working with mental health professionals, and presenting compelling evidence to the court. That’s where Combs Waterkotte comes in. With our proven track record in high-stakes cases and dedication to personalized defense strategies, we are equipped to successfully work for your acquittal. Contact us online or call (314) 900-HELP for a free consultation and let our experienced St. Louis criminal defense attorneys fight to preserve your future.