By David Lombard, PhD, Licensed Psychologist and Forensic Evaluator
The legal test for insanity in Indiana does not change when the charge is murder. Almost everything about how the evaluation is done does.
Under Indiana law, a person is not responsible for criminal conduct if, as a result of mental disease or defect, they were unable to appreciate the wrongfulness of that conduct at the time of the offense. The defendant carries the burden of proving that by a preponderance of the evidence. Those rules apply equally to a residential entry and to a homicide. But a criminal responsibility evaluation in a homicide case looks very different.
In practice, though, homicide cases bring a larger record, closer scrutiny, a different panel of court-appointed evaluators, and far higher stakes for every opinion an expert offers. For defense attorneys and prosecutors who have handled insanity claims before but are facing one in a homicide for the first time, here is what to expect.
The Record Is Bigger, and It Matters More
A homicide file is usually the most complete record of a defendant's behavior that will ever exist. A thorough evaluation draws on all of it, not just the interview. Typical sources include:
• 911 calls and dispatch audio
• Body camera and dash camera footage
• Recorded interrogations and jail phone calls
• Witness statements from before and after the event
• Autopsy and crime scene findings
• Prior mental health, medical, school, and military records
• Social media, texts, and writings from the days leading up to the offense
The defendant's own account is the least reliable source in the file, because it is the one most shaped by the stakes. Indiana appellate courts have upheld juries that rejected favorable expert opinions where the evaluators relied mainly on the defendant's self-report. An opinion built on the full record is much harder to set aside.
For attorneys, the practical point is simple: get the evaluator the discovery early, and get all of it. An expert who has not reviewed the interrogation video is going to be asked why on cross-examination.
Reconstructing One Moment in Time
A criminal responsibility evaluation is retrospective. The question is not how the defendant is functioning in the jail interview room today. It is what was happening in the defendant's mind at the moment of the offense, often months or years earlier.
Evaluators reconstruct that moment by looking at behavior in three windows:
1. Before the offense. Was there a decline in functioning, emerging delusions, missed medications, sleep loss, or statements that suggest a break from reality? Or was there planning, acquiring a weapon, or expressed motive?
2. During the offense. What do witnesses, recordings, and physical evidence show about the defendant's organization, speech, and goals?
3. After the offense. Did the defendant flee, hide evidence, lie to police, or call for help? What did they say, and to whom?
In Indiana, this kind of "demeanor evidence" can carry significant weight with a jury, even against unanimous expert testimony. Flight or concealment is often argued as proof the defendant knew the act was wrong.
A careful evaluator does not accept that inference automatically. A person in a psychotic state may hide from police because they believe the officers are part of a plot, not because they understand the killing was unlawful. The Indiana Supreme Court has also recognized limits: in Payne v. State (2020), it reversed a guilty but mentally ill verdict where the State's demeanor evidence was too thin to overcome unanimous expert opinion and a long documented history of serious mental illness. The evaluator's job is to explain what the behavior actually reflects, given everything else in the record.
Malingering and Response Style Get Closer Scrutiny
The higher the stakes, the stronger the incentive to exaggerate or invent symptoms. Every competent forensic evaluator assesses response style, and in homicide cases opposing counsel will press hard on how that was done.
A defensible approach does not rest on a single test score. It looks for convergence across several lines of evidence:
• Validated symptom validity and performance validity measures, chosen for the defendant's presentation
• Consistency between reported symptoms and what is known about how real disorders present
• Consistency between the defendant's account and the recorded, observed behavior at the time
• Collateral reports from family, jail staff, and treatment providers
• Whether symptoms appear only in evaluation settings or across the person's daily life
The reverse problem matters too. Some defendants with genuine psychotic illness minimize their symptoms because they do not want to be seen as "crazy." An evaluator who only screens for exaggeration can miss real impairment.
Cooperation also has legal consequences in Indiana. If a defendant is ordered to participate with the court-appointed evaluators and does not, the defendant may lose the ability to present testimony from their own retained mental health expert, unless the failure to cooperate was caused by mental illness.
Intoxication and Co-occurring Conditions
Many homicides involve alcohol or drugs, and this is one of the most contested areas in criminal responsibility work.
Indiana does not allow voluntary intoxication to serve as a defense. But substance use at the time of the offense does not automatically rule out insanity either. The key questions are:
• Was there an underlying mental illness that would have produced the impairment with or without the substance?
• Did long-term use cause a lasting condition, sometimes called "settled" or "fixed" insanity, that persists beyond the period of intoxication? Indiana courts have recognized this doctrine.
• Was the substance use itself a symptom, such as self-medication of emerging psychosis?
Sorting this out requires a detailed timeline of use, symptoms, and treatment, ideally supported by toxicology and records rather than recollection. It is also an area where the evaluator's reasoning needs to be especially transparent, because the line between intoxication and illness is exactly where the opposing expert will focus. (We covered how evaluators document that reasoning in How Forensic Evaluators Document and Defend Their Reasoning.)
The Indiana Process: A Different Panel for Homicide Cases
Indiana's insanity statute has a provision that applies only to homicide charges. Once the defense files notice of an insanity defense (for felonies, no later than 20 days before the omnibus date, unless the court allows later filing for good cause), the court appoints two or three disinterested experts to examine the defendant and testify.
In most cases, at least one of those experts must be a psychiatrist or a psychologist. In homicide cases, the panel must include at least one psychiatrist and at least one psychologist. That means a homicide jury will usually hear from both disciplines, each bringing different tools: the psychiatrist's medical and pharmacological perspective, and the psychologist's standardized testing and response-style assessment.
The court-appointed experts testify after both sides have presented their evidence, including any retained experts, and both sides may cross-examine them. In practice, their opinions often frame how the jury weighs everything else.
When the insanity defense is raised, the jury has four possible verdicts:
| Verdict | What it means in practice |
|---|---|
| Guilty | Standard conviction and sentence |
| Not guilty | Acquittal on the charge |
| Not responsible by reason of insanity | No criminal conviction; the State petitions for civil commitment, and the court holds a commitment hearing |
| Guilty but mentally ill | Same sentence as a guilty verdict, with evaluation and treatment for the mental illness during incarceration |
The guilty but mentally ill option matters a great deal in homicide trials. It gives jurors a middle path when they believe the defendant is seriously ill but are not persuaded the illness prevented them from appreciating wrongfulness. For more on what happens after an insanity verdict, see Understanding "Not Guilty by Reason of Insanity" Outcomes After Verdict.
When to Bring In a Consultant
The most useful time to involve a forensic psychologist is before the notice of insanity defense is filed, not after the court-appointed panel has reported.
An early, confidential consultation can help counsel answer practical questions:
• Is there a credible mental state issue here, or is this better addressed at sentencing?
• Is the real question insanity, or is it competency to stand trial? (Those are different questions, covered in Competency Restoration Programs: What Actually Happens During Treatment.)
• What records and recordings need to be preserved and gathered now?
• What will the court-appointed experts likely focus on, and where are the weak points?
Filing an insanity notice also opens the door to State examination and broad admissibility of mental health evidence. That decision is easier to make well with a clear-eyed read of the record first. We will look more closely at pretrial consultation in next week's post.
Frequently Asked Questions
Is the insanity standard different for murder in Indiana? No. The same test applies to every offense: whether, because of mental disease or defect, the defendant was unable to appreciate the wrongfulness of the conduct at the time of the offense. What differs in homicide cases is the makeup of the court-appointed panel and the depth of the evaluation.
Who has to prove insanity? The defendant, by a preponderance of the evidence. It is an affirmative defense.
Does fleeing the scene mean the defendant knew it was wrong? Not necessarily. Flight and concealment are often argued that way, and juries may weigh them heavily. A forensic evaluator considers whether that behavior was driven by an understanding of wrongfulness or by delusional beliefs, fear, or other symptoms.
Can someone who was drunk or high at the time be found insane? Voluntary intoxication alone is not a defense in Indiana. Insanity can still apply if an underlying mental illness, or a lasting condition caused by long-term substance use, prevented the person from appreciating wrongfulness.
What is the difference between "not responsible by reason of insanity" and "guilty but mentally ill"? A finding of not responsible results in no criminal conviction and leads to civil commitment proceedings. Guilty but mentally ill is a conviction with the same sentence as a guilty verdict, plus mental health evaluation and treatment.
Is insanity the same as diminished capacity? No. They are distinct concepts that are frequently confused. We will cover the difference in an upcoming post.
Consult on a Homicide Case
If you are evaluating whether a mental state defense is viable in a homicide case, or need a review of an existing criminal responsibility report, I offer confidential case consultation and independent evaluations. Contact me through davidlombard.com to discuss your case.
David Lombard, PhD, is a licensed psychologist providing forensic evaluations and expert consultation in criminal and family law matters in Indiana.
This article is for general educational purposes and is not legal advice.