Not Guilty by Reason of Insanity in Colorado: Plea, Proof, and Release

In Colorado, a defendant can enter a plea of not guilty by reason of insanity when a severe mental disease or defect left them unable to tell right from wrong at the time of the offense. What sets Colorado apart from most states is who has to prove what: once the defense puts any evidence of insanity on the table, the prosecution must prove the defendant was sane beyond a reasonable doubt. A successful plea does not mean the defendant walks out of the courthouse. It means indefinite commitment to a state psychiatric hospital, with release tied to a stricter test than the one used to establish insanity in the first place.

How Colorado Defines Legal Insanity

The definition sits in Section 16-8-101.5 of the Colorado Revised Statutes. A person is not criminally accountable if, at the time of the act, they were “so diseased or defective in mind” that they could not distinguish right from wrong with respect to that act.¹ This is a cognitive test rooted in the M’Naghten Rule. It asks a narrow question. Did the illness destroy the defendant’s ability to understand that what they were doing was wrong?

The Colorado Supreme Court has clarified in People v. Serravo that “wrong” means morally wrong under society’s existing standards, not merely illegal, and not the defendant’s own private moral code.² A defendant whose delusions made them unable to grasp that society considers an act wrong can meet the standard. A defendant who simply disagreed with the law cannot.

What Counts as a Mental Disease or Defect

The statute is deliberately narrow. It reaches only severely abnormal mental conditions that “grossly and demonstrably” impair a person’s perception or understanding of reality.¹ Psychotic illnesses like schizophrenia or severe bipolar disorder with psychotic features typically fit. A diagnosis by itself does not. The impairment has to be gross and it has to be demonstrable.

What the Statute Excludes

Several conditions are ruled out by name:

Voluntary intoxication from alcohol or any other psychoactive substance the defendant chose to consume, even if the resulting state resembles psychosis.
An abnormality shown only by repeated criminal or antisocial conduct. Antisocial personality disorder standing alone does not qualify.
“Moral obliquity, mental depravity, or passion growing out of anger, revenge, hatred, or other motives.” Rage and revenge are not insanity, however extreme the conduct.¹

Who Has to Prove What

This is the part most people get wrong. In Colorado, the defense only needs to introduce some evidence of insanity. Once it does, the prosecution must prove sanity beyond a reasonable doubt, the same standard used to prove guilt itself.³

Most states put the burden the other way. Defendants in those states must prove insanity by a preponderance of the evidence. Federal defendants must prove it by clear and convincing evidence. Colorado is one of a small group of jurisdictions where the government carries the weight of disproving the defense.

Entering the Plea

The plea is entered orally at arraignment, either by the defendant personally or through the attorney. A later plea is possible only for good cause.⁴ Before accepting the plea, the judge must advise the defendant what it actually means, including the possibility of indefinite commitment to a state psychiatric facility if it succeeds.

An NGRI plea automatically includes a standard not guilty plea. If the jury rejects insanity, the case does not slide straight into conviction. The jury still has to decide whether the prosecution proved every element of the underlying crime beyond a reasonable doubt.⁴

There is also an unusual provision for defendants who refuse to plead insanity when their attorney believes the plea is necessary. Counsel can inform the court. The court can then investigate, appoint psychiatrists or forensic psychologists to examine the defendant, and enter the plea over the defendant’s objection if it finds the plea necessary for a just outcome.

The Sanity Examination

Once the plea is entered, the court orders a sanity examination. The defendant may be sent to the Colorado Mental Health Hospital in Pueblo, kept at the facility where they are already in custody, or evaluated at another designated public institution, with priority given to their current place of custody unless a specialized facility is needed.⁵

One or more psychiatrists or forensic psychologists conduct the evaluation over a period the court sets. They review medical history, run clinical interviews and psychological testing, and analyze the circumstances of the offense. The point is to reconstruct the defendant’s mental state at the moment of the crime and measure it against the statutory test. Findings go to the court in a report, and any recorded portions of the evaluation may be shared with both sides.

Experts at Trial

The report is central but not final. Both sides can call their own psychiatrists or forensic psychologists, and the prosecution can request an independent evaluation if it disputes the initial findings. For good cause, the court can order additional evaluations beyond the first.⁵ Cross-examination of these experts is usually where the case is won or lost, because jurors are being asked to weigh competing professional opinions about something no one can observe directly — a defendant’s state of mind months or years earlier.

What an NGRI Verdict Actually Means

A successful insanity defense does not end in release. The court commits the defendant to the custody of the Colorado Department of Human Services, which places them in an appropriate state facility, typically the Colorado Mental Health Hospital in Pueblo.⁶

There is no fixed term. Commitment lasts until the defendant meets the legal test for release, and some individuals remain hospitalized for years or decades.³ It can exceed the sentence a conviction would have carried.

A Narrow Exception for Less Serious Offenses

For certain nonviolent offenses, the court can delay formal entry of the verdict and stay commitment, allowing the defendant to remain on bond pending an initial release hearing. The exception does not apply if the crime was a class 1 or class 2 felony, resulted in serious bodily injury or death, involved a deadly weapon, or involved felony unlawful sexual behavior.³

Getting Out: The Release Test

Release from commitment requires meeting all three parts of a specific legal test. For offenses committed on or after July 1, 1983, the defendant must show they have no abnormal mental condition likely to make them dangerous to themselves, others, or the community in the reasonably foreseeable future; that they are capable of distinguishing right from wrong; and that they have substantial capacity to conform their conduct to the requirements of law.⁷

That test is stricter than the insanity test itself. Insanity turns on a single cognitive question. Release adds behavioral capacity and a finding of low future dangerousness.

Hearing Schedule and Annual Reports

A defendant can request a release hearing 182 days after the initial commitment. After that first hearing, hearings are generally limited to once a year unless the court finds good cause for more frequent review.⁸

Since September 2022, the chief officer of the committing facility must submit an annual release examination report to the court certifying whether the defendant still needs inpatient hospitalization or meets the release test. Copies go to the defendant, the prosecutor, and any attorney of record, and any of them can request a hearing based on the report.⁸ Before that change, documented cases showed individuals held for years without meaningful review, some receiving as little as two hours of therapy despite no longer needing hospitalization.

Conditional Release

If the court finds a defendant eligible for release, it can impose conditions such as ongoing psychiatric evaluations, medication compliance, and restrictions on activities or locations. Violations can trigger recommitment, and the court retains oversight throughout.⁸ Victims and immediate family members must be notified before any release hearing when they can reasonably be located, and they have the right to give written or oral testimony.

If the Insanity Defense Fails

Because the NGRI plea folds in a not guilty plea, a failed insanity defense is not an automatic conviction. The jury first decides the insanity question. If it rejects insanity, it moves to the underlying charges and applies the ordinary reasonable-doubt standard to each element. A conviction there produces standard sentencing.

The James Holmes case is the well-known illustration. Holmes pleaded not guilty by reason of insanity for the 2012 Aurora theater shooting that killed 12 people and injured dozens more. All mental health experts who evaluated him agreed he would not have committed the killings but for his mental illness, but they disagreed on whether he could appreciate the criminality of his conduct. The jury rejected the insanity defense, convicted him on all charges, and he was sentenced to life in prison without the possibility of parole.⁹ Undisputed mental illness is not enough. The question is always whether the illness eliminated the ability to tell right from wrong.

Competency to Stand Trial Is Not the Same Thing

Insanity and competency get confused constantly. They ask different questions at different times. Competency asks about the defendant’s mental state right now: can they understand the charges and work with their lawyer? Insanity asks about the defendant’s mental state at the moment of the crime.

Someone with schizophrenia stabilized on medication can be perfectly competent to stand trial while having been floridly psychotic during the offense. A defendant found incompetent today may have been fully lucid when the crime occurred. The U.S. Supreme Court’s Dusky v. United States decision set the competency standard, requiring a rational and factual understanding of the proceedings and the ability to consult with counsel.¹⁰ If a defendant is found incompetent, the trial pauses for restoration treatment. Insanity is only litigated once the defendant is competent enough to stand trial.

How Often the Defense Actually Succeeds

Public perception runs well ahead of the numbers. An eight-state study published by the American Academy of Psychiatry and the Law found the insanity defense was raised in about one percent of all felony cases, and only about 26 percent of those who raised it were acquitted.¹¹ It is a narrow path, and it rarely ends the way the public assumes. Acquittal leads to a locked psychiatric facility, not the street, and release depends on satisfying a clinical and legal test that many defendants never meet.

1
Justia. Colorado Code 16-8-101.5 – Insanity Defined
2
Justia. People v. Serravo
3
Justia. Colorado Code 16-8-105.5 – Procedure After Plea for Offenses Committed on or After July 1, 1995
4
Justia. Colorado Code 16-8-103 – Pleading Insanity as a Defense
5
Justia. Colorado Code 16-8-106 – Examinations and Report
6
Colorado Department of Human Services. About the Colorado Mental Health Hospital in Pueblo
7
Justia. Colorado Code 16-8-120 – Test for Eligibility for Release
8
Justia. Colorado Code 16-8-115 – Release From Commitment After Verdict of Not Guilty by Reason of Insanity or Not Guilty by Reason of Impaired Mental Condition
9
Death Penalty Information Center. Mentally Ill James Holmes Sentenced to Life in Prison in Aurora, CO Theater Shooting
10
Justia. Dusky v. United States
11
The American Academy of Psychiatry and the Law. The Volume and Characteristics of Insanity Defense Pleas – An Eight-State Study