A first-degree murder charge in Illinois can expose an accused person to decades—or potentially the remainder of his or her life—in prison.
But proving that someone caused another person’s death does not always answer the most important legal question.
Was the accused legally responsible for his or her actions at the time of the killing?
When severe mental illness, psychosis, delusions, hallucinations, or another serious mental disease or defect affected the accused’s ability to understand the criminality of the conduct, Illinois law provides a powerful—but demanding—defense:
Not Guilty by Reason of Insanity.
An insanity defense is not simply an argument that the accused suffered from mental illness. It is a legal defense to criminal responsibility itself.
And in a first-degree murder prosecution, properly identifying and developing that defense can fundamentally change the case.
Illinois Law Recognizes That Mental Illness Can Eliminate Criminal Responsibility
Under 720 ILCS 5/6-2, a person is not criminally responsible for conduct when, because of a mental disease or mental defect, the person lacked substantial capacity to appreciate the criminality of the conduct at the time it occurred.
That language matters.
The defense does not have to prove merely that the accused had been diagnosed with a psychiatric condition.
It must demonstrate how that condition affected the accused’s mind at the moment of the alleged killing.
That is why an insanity defense in a murder case cannot be built simply by obtaining a diagnosis and placing a psychiatrist on the witness stand.
It requires reconstructing the accused’s mental state.
A Diagnosis Is Not Enough
Schizophrenia. Psychosis. Bipolar disorder. Delusions. Hallucinations. Severe psychiatric disease.
Any of these may become extraordinarily important in a first-degree murder prosecution.
But none automatically establishes legal insanity.
A person can suffer from a serious psychiatric disorder and still be considered legally responsible for his or her actions.
The real question is much more specific:
Did the mental disease or defect deprive the accused of substantial capacity to appreciate that the conduct was criminal?
Consider a defendant suffering from a severe psychotic episode.
If that person understands reality and appreciates that killing another person is criminal, an insanity defense may fail despite the psychiatric diagnosis.
But imagine a defendant experiencing profound delusions who perceives an entirely different reality—one created by severe mental disease—and, because of that disease, lacks substantial capacity to appreciate the criminality of the conduct.
That is an entirely different case.
The distinction can determine whether the accused is convicted of first-degree murder or found not guilty by reason of insanity.
The Defense Must Reconstruct the Accused’s Mind
In a serious murder prosecution involving mental illness, the defense should investigate far beyond the police reports.
The accused’s mental state must be reconstructed from every available source.
That may include:
- psychiatric hospitalization records;
- prior diagnoses and psychological evaluations;
- prescription and medication histories;
- evidence that psychiatric medication was discontinued or changed;
- previous psychotic episodes;
- documented hallucinations or delusions;
- statements to family members and friends;
- text messages, emails, internet activity, and social-media communications;
- 911 recordings;
- surveillance video;
- police body-camera footage;
- interrogation recordings;
- medical records;
- witnesses who observed unusual behavior before or after the incident; and
- forensic psychiatric and psychological evaluations.
Sometimes the strongest evidence of insanity existed before anyone knew a homicide was going to occur.
A text message sent three days earlier. A psychiatrist’s note from months before. A family member who watched the accused deteriorate psychologically. A prescription that suddenly stopped being filled. A delusion repeatedly described long before the alleged offense.
Those facts can become critical because they may demonstrate that the claimed mental illness was not manufactured after an arrest.
What the Accused Did After the Killing Can Matter
Prosecutors frequently rely on evidence of planning, concealment, flight, false statements, destruction of evidence, or other conduct following an alleged homicide to argue that the accused understood what he or she was doing.
The defense must be prepared to confront that evidence.
But human behavior during severe mental illness does not always fit neatly into the prosecution’s theory.
A person experiencing psychosis may still perform complicated tasks. Someone suffering from delusions may appear rational when discussing unrelated subjects. A severely mentally ill person may take actions that appear calculated when viewed outside the context of the person’s distorted perception of reality.
That is why an insanity case should not be reduced to isolated conduct selected by the prosecution.
The defense must present the complete psychiatric picture.
The Defendant Bears a Significant Burden
Insanity is an affirmative defense under Illinois law.
The defendant bears the burden of establishing that he or she was not guilty by reason of insanity by clear and convincing evidence.
The State still must prove the elements of first-degree murder beyond a reasonable doubt.
This burden makes preparation critical.
A successful insanity defense cannot rest on speculation, sympathy, or a generalized claim that the accused was mentally ill.
It must be supported by evidence.
Records. Witnesses. History. Conduct. Expert analysis.
And those pieces must be assembled into a coherent explanation of the accused’s mental condition when the alleged homicide occurred.
Prosecutors Will Fight an Insanity Defense
In a first-degree murder prosecution, the State is unlikely to accept an insanity claim simply because the defense produces a psychiatric expert.
Prosecutors may retain their own experts. They may attack the accused’s diagnosis. They may argue that symptoms were exaggerated or fabricated. They may point to evidence of planning or concealment as proof that the accused appreciated the criminality of the conduct.
They may also use the accused’s own statements against the defense.
That makes the selection and preparation of forensic experts exceptionally important.
The defense lawyer must also understand the psychiatric evidence well enough to challenge the State’s experts through cross-examination.
An insanity case can therefore become a battle between competing interpretations of the accused’s mental state.
The defense must be prepared to win that battle.
Insanity Is Not the Same as Guilty But Mentally Ill
Illinois law draws an important line between legal insanity and mental illness.
A defendant can be severely mentally ill and still be criminally responsible.
Illinois therefore recognizes a separate verdict of guilty but mentally ill.
That verdict is dramatically different from not guilty by reason of insanity.
A person found guilty but mentally ill has still been convicted of the crime.
For someone charged with first-degree murder, that distinction can have enormous consequences.
The defense therefore cannot allow the case to become merely about whether the accused suffered from psychiatric problems.
The issue must remain focused on the statutory question:
Did the mental disease or defect cause the accused to lack substantial capacity to appreciate the criminality of the conduct?
Insanity Is Also Different From Fitness to Stand Trial
Another critical distinction is between insanity and fitness.
Insanity looks backward.
It asks about the accused’s mental condition when the alleged crime occurred.
Fitness looks at the present.
It asks whether the accused currently understands the nature and purpose of the proceedings and can assist counsel in the defense.
A person may have been legally insane when a homicide occurred but later become fit for trial after receiving psychiatric treatment.
Conversely, someone may have been legally sane when an alleged offense occurred but later become unfit to stand trial.
When serious mental illness is present, both issues may require investigation—but they are separate legal questions.
An Insanity Defense Should Be Investigated Immediately
Time matters.
Psychiatric evidence can disappear.
Witnesses forget what they observed. Electronic communications are deleted. Surveillance footage is overwritten. Medical providers change. Records become more difficult to locate.
Most importantly, the accused’s psychiatric condition may change dramatically after arrest.
Medication and treatment can stabilize someone who was profoundly psychotic when the alleged offense occurred. Months later, the person sitting in a courtroom may look nothing like the person witnesses encountered during the period surrounding the homicide.
The defense therefore should begin documenting the accused’s psychiatric condition as early as possible.
Waiting until trial approaches can mean losing evidence that cannot be recreated.
A First-Degree Murder Case Requires More Than a Routine Defense
When the government charges someone with murder, the defense cannot afford assumptions.
Every viable defense must be investigated.
That includes mental-health defenses.
At Pissetzky Law, we defend individuals accused of first-degree murder, violent crimes, and other serious felony offenses in Chicago and throughout Illinois.
When severe mental illness may have played a role in an alleged homicide, we do not stop at asking whether the accused has a psychiatric diagnosis.
We investigate the deeper question:
What was happening inside the accused’s mind when the alleged offense occurred?
That means examining psychiatric records, hospitalization histories, medications, witnesses, electronic evidence, police recordings, interrogation statements, forensic evaluations, and the accused’s behavior before, during, and after the incident.
We work with qualified experts when necessary and prepare to challenge the prosecution’s psychiatric evidence in court.
Because in a first-degree murder prosecution, an insanity defense should never be an afterthought.
If the evidence shows that severe mental disease prevented the accused from appreciating the criminality of his or her actions, that evidence can go directly to whether the accused should be held criminally responsible at all.
Contact an Illinois First-Degree Murder Defense Lawyer
If you or a family member has been charged with first-degree murder in Illinois and there is a history of schizophrenia, psychosis, delusions, hallucinations, bipolar disorder, psychiatric hospitalization, or other serious mental illness, the mental-health evidence should be investigated immediately.
Do not assume that a psychiatric diagnosis automatically establishes insanity.
And do not assume that mental illness is irrelevant simply because the prosecution believes the killing was intentional.
The legal question is far more complicated.
Pissetzky Law represents individuals facing first-degree murder and other serious criminal charges in Chicago, Cook County, Lake County, DuPage County, Will County, Kane County, and throughout Illinois.
When the stakes are this high, the defense should investigate every fact, every expert issue, and every available defense before the prosecution gets to define what happened.