A Not Guilty by Reason of Insanity plea in Wisconsin, commonly called an NGI plea, does not deny that the defendant committed the charged act. It argues that a mental disease or defect left the defendant without the capacity to be held criminally responsible for it. When the plea succeeds, the court commits the defendant to the Department of Health Services for treatment and supervision, and that commitment can last as long as the maximum prison term the crime carried.
The Legal Standard
Wisconsin Statute 971.15 sets the test. A person is not criminally responsible if, at the time of the offense, a mental disease or defect left them without the substantial capacity either to appreciate the wrongfulness of their conduct or to conform their behavior to the law.1Wisconsin State Legislature. Wisconsin Code 971.15 – Mental Responsibility of Defendant Either prong will do. A defendant who understood that what they were doing was wrong but could not control their behavior can still qualify.
The statute also narrows what counts as a mental disease or defect. An abnormality that shows up only as repeated criminal or antisocial behavior does not qualify.1Wisconsin State Legislature. Wisconsin Code 971.15 – Mental Responsibility of Defendant A pattern of lawbreaking by itself is not a mental illness for NGI purposes. The defense needs a recognized psychiatric condition, backed by clinical history, that affected the defendant’s functioning at the time of the offense.
Entering the Plea
Wisconsin Statute 971.06 lists NGI as one of the pleas available to a criminal defendant.2Wisconsin State Legislature. Wisconsin Code 971.06 – Pleas It is almost always joined with a standard not guilty plea. Together they trigger a two-phase trial where the jury decides guilt first and mental responsibility second.
An NGI plea can also be entered alone. Doing so effectively admits every element of the charged offense, leaving only the question of mental responsibility for the court to decide.2Wisconsin State Legislature. Wisconsin Code 971.06 – Pleas That removes any chance of an outright acquittal, so defense attorneys rarely take that route unless the evidence of guilt is overwhelming and the mental health case is strong.
How the Trial Works
When both pleas are entered, Wisconsin Statute 971.165 requires the trial to unfold in two separate phases, heard in sequence during a continuous proceeding.3Wisconsin State Legislature. Wisconsin Code 971.165 – Trial of Actions Upon Plea of Not Guilty by Reason of Mental Disease or Defect The split keeps psychiatric evidence out of the jury’s decision on whether the defendant actually committed the crime.
In the first phase, the prosecution must prove the offense beyond a reasonable doubt. Mental health plays no role. If the jury acquits, the court enters judgment and the defendant goes free. The case never reaches the insanity question.3Wisconsin State Legislature. Wisconsin Code 971.165 – Trial of Actions Upon Plea of Not Guilty by Reason of Mental Disease or Defect
If the jury returns a guilty verdict, the court holds off on judgment and moves to the second phase. The focus shifts to the defendant’s mental state at the time of the offense. The defense presents psychiatric evaluations, medical records, and expert testimony. The prosecution counters with its own experts, often challenging the severity of the illness or arguing the defendant retained more control than claimed. The same jury usually decides both phases, though the statute permits a different jury if the first is discharged before reaching a verdict on the second plea.3Wisconsin State Legislature. Wisconsin Code 971.165 – Trial of Actions Upon Plea of Not Guilty by Reason of Mental Disease or Defect
Who Has to Prove What
The burden flips between phases. The prosecution carries the beyond-a-reasonable-doubt burden on guilt in phase one. In phase two, the insanity defense is an affirmative defense, and the defendant must establish it “to a reasonable certainty by the greater weight of the credible evidence.”1Wisconsin State Legislature. Wisconsin Code 971.15 – Mental Responsibility of Defendant That standard sits below beyond a reasonable doubt, but the “reasonable certainty” qualifier means the defense needs more than a bare tipping of the scales.
The Forensic Evaluations
Expert testimony drives phase two. Under Wisconsin Statute 971.16, the court may appoint one to three physicians or psychologists to examine the defendant and testify. The county pays for these court-appointed evaluations, and the jury is told the examiners were court-selected.4Wisconsin State Legislature. Wisconsin Code 971.16 – Examination of Defendant
Each court-appointed examiner files a written report at least ten days before trial, addressing whether the defendant could appreciate the wrongfulness of the conduct or conform to the law at the time of the offense. The defense may retain its own experts, who get reasonable access for an independent examination. If the defense uses its own expert, the report must be shared with the prosecution at least fifteen days before trial, and the state is entitled to its own examination of the defendant.4Wisconsin State Legislature. Wisconsin Code 971.16 – Examination of Defendant Prosecutors sometimes argue the defendant is malingering, meaning exaggerating or fabricating symptoms. Courts weigh competing evaluations against the defendant’s documented psychiatric history, medication records, and prior hospitalizations.
One point of confusion worth clearing up: the Wisconsin Forensic Unit does not conduct NGI evaluations. The WFU handles competency evaluations, which are a separate process funded by the Department of Health Services. NGI evaluations require an independent court-appointed examiner, and the cost falls on the county or the defendant.5Wisconsin Community Services. Frequently Asked Questions
What Happens If the Plea Succeeds
A successful NGI defense does not mean walking out of the courthouse. The court commits the defendant to the Department of Health Services, and the initial order specifies either institutional care or conditional release.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect
Institutional Care or Conditional Release
The court orders institutional care if it finds, by clear and convincing evidence, that conditional release would pose a significant risk of bodily harm to the person or others, or a risk of serious property damage. Without that finding, the court must order conditional release.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect Factors the court may weigh include the nature of the crime, mental health history and current condition, living arrangements, means of support, medication access and compliance, and available treatment.
Institutional care means placement in a facility selected by the Department of Health Services under Wisconsin Statute 51.37(3), based on rehabilitative needs and public safety considerations. Conditional release means living in the community under strict supervision, with mandatory treatment, regular contact with case managers, and individualized conditions set by the court.
How Long the Commitment Lasts
For felonies committed on or after July 30, 2002, the commitment cannot exceed the maximum prison term that could have been imposed for the same felony, including any penalty enhancements. For a felony punishable by life imprisonment, the court may order a life commitment, subject to the person’s right to petition for termination. Credit for time already spent in custody applies. When the commitment order expires, the court must discharge the person, though the Department of Health Services or the appropriate county department can initiate civil commitment proceedings if the person still meets civil commitment standards.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect
Petitioning for Release
A person in institutional care can petition for conditional release. The court appoints an examiner, and a hearing is held within thirty days after the report is filed. The burden sits with the state, not the person seeking release: the court grants the petition unless the state proves by clear and convincing evidence that release would pose a significant risk of bodily harm or serious property damage.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect
A person already on conditional release can petition to terminate the commitment order entirely. The court terminates it unless the state proves by clear and convincing evidence that continued supervision is needed to prevent a significant risk of harm. A termination petition cannot be filed until at least six months have passed since the person was last placed on conditional release or since the most recent petition was denied.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect A person filing without an attorney is referred to the state public defender for an indigency determination.
Conditional release can also be revoked. If the Department of Health Services believes a condition has been violated or that public safety requires it, the department can take the person into custody and must file a revocation petition with the committing court within seventy-two hours.6Wisconsin State Legislature. Wisconsin Code 971.17 – Commitment of Persons Found Not Guilty by Reason of Mental Disease or Mental Defect
Firearm Consequences
An NGI finding for a felony triggers a firearm ban under Wisconsin Statute 941.29. A person found not guilty of a felony by reason of mental disease or defect commits a Class G felony by possessing a firearm, punishable by up to ten years of imprisonment.7Wisconsin State Legislature. Wisconsin Code 941.29 – Possession of a Firearm
The restriction can be lifted, but only if a court finds both that the person no longer has a mental disease, defect, or illness, and that the person is not likely to act in a manner dangerous to public safety.7Wisconsin State Legislature. Wisconsin Code 941.29 – Possession of a Firearm Until a court makes both findings, the ban stays in place even after discharge from commitment.
NGI Is Not the Same as Competency to Stand Trial
These two ideas get mixed up constantly, and they ask different questions about different moments in time. Competency to stand trial, governed by Wisconsin Statute 971.14, asks whether the defendant can understand the proceedings and work with counsel right now. If not, the case pauses for treatment until competency is restored. The insanity defense looks backward, at the defendant’s mental state during the offense.1Wisconsin State Legislature. Wisconsin Code 971.15 – Mental Responsibility of Defendant A defendant can be fully competent today and still have been legally insane at the time of the crime. The two evaluations happen separately, use different examiners, and answer different legal questions.