By Reason of Insanity

Mental illness defenses in criminal trials have been controversial since the first acquittal. How does the law define madness?

April 24, 2015

Mike Mariani is a writer and educator based in Hoboken, NJ. His work has appeared in LA Review of Books, Pacific Standard, The Atlantic, and This Land...

On June 25, 2012, James Eagan Holmes emailed Glenn Rotkovich, the owner of the Lead Valley shooting range in Byers, Colorado, inquiring about becoming a member. Over the next few days, Rotkovich telephoned him several times. Each call went to the same unnerving voicemail—guttural, discursive, like Holmes was talking to himself, or acting out some bizarre performance. "In hindsight, looking back—and if I'd seen the movies—maybe I'd say it was like the Joker,” Rotkovich would later tell

About two weeks after he sent this email, the New York Times reported, Holmes texted one of his classmates in the Neuroscience PhD program at the University of Colorado Anschutz. He asked her if she'd heard of “dysphoric mania,” an unusual manifestation of bipolar disorder in which a person experiences symptoms of mania and depression simultaneously. He later texted her to steer clear of him "because I am bad news."

On July 20, Holmes entered a screening of The Dark Knight Rises at the Century 16 movie theater in Aurora, Colorado, clad in military-grade ballistic gear. He was armed to the teeth with a semiautomatic M-16 rifle, a 12-gauge shotgun, and a .40-caliber pistol. After the smoke cleared from the barrage of gas canisters Holmes set off in the theatre, 12 people were dead and 70 injured. Police apprehended him outside the theatre almost immediately.

Holmes' defense team originally planned to enter a plea of diminished capacity, arguing that the accused was mentally impaired at the time of the crime and could not be held fully responsible. But on March 27, 2013, they changed their plea to guilty as an offer to the prosecution in order to avoid the death penalty. The prosecution didn’t accept.

Left with little choice, Holmes' defense pleaded not guilty by reason of insanity on June 4. Since then, they have argued that Holmes "suffers from a severe mental illness and was in the throes of a psychotic episode” when he entered that movie theatre.

The level of premeditation casts doubt on whether Holmes’ rampage can be understood solely as the actions of a man in the midst of such an episode. The erstwhile PhD student had been stockpiling guns and ammunition for months leading up to the attack, spending thousands online to fortify his arsenal and perfect his SWAT gear flourishes. According to FBI agents, Holmes booby-trapped his own apartment, using a host of explosive materials rigged to go off and divert the authorities from his killing spree at the movie theatre. This, it seems, was a highly sophisticated, multifaceted plan set in place months before the shootings.

The forthcoming trial, set to begin April 27, is a rare species: Holmes is one of a few mass shooters to not either commit suicide or be killed by police in the act. One of the major questions hanging over the case is whether Holmes' defense really has a legitimate argument in their plea of not guilty by reason of insanity. In a country in which anywhere from 15 to 20 percent of the incarcerated population suffers from severe mental illness, it’s still unclear exactly where the line between those with mental afflictions who are held responsible for their crimes and those who are not truly is.

Was Holmes really insane at the time of the shooting? And more importantly, is the U.S. justice system's definition of insanity flexible enough to free the defendant from culpability for his crimes?


For centuries, courts have struggled to protect the mentally ill while also trying to distinguish between sanity and insanity. In the 1700s, the British courts relied on the “wild beast” test as their barometer for the latter: if the defendant’s understanding of his crime was no better than that of a infant or beast, he couldn’t be found guilty. From there, the insanity defense began its tortuous evolution.

In 1843, a Scottish woodcutter named Daniel M'Naghten attempted to assassinate British Prime Minister Robert Peel, shooting and killing his secretary instead. M'Naghten believed that Peel and the British government had singled him out for persecution and were responsible for all his personal and financial woes. He was found not guilty by reason of insanity and acquitted, leading to public outrage over the verdict.

In response, the House of Lords and a panel of the Queen's judges put together the M'Naghten Rules, a specific, multifaceted bar the defense was required to clear in order to prove not just plain old madness, but exculpatory insanity. They established a presumption of sanity, shifting the burden of proof solely to the defense.

The M’Naghten Rules were embraced in American courts and presided as the legal standard for more than a century. But by the 1950s, modern psychology was reaching a tipping point. Though William James' The Principles of Psychology had been around since 1890, the field had generally been confined to the insulated world of academia. But people were finding new ways to talk about psychology in the appealing terms of magazine articles, self-help books, and radio programs. Pop psychology was born.

In the 1953 case of Durham v. U.S., 23-year-old Monte Durham was convicted of housebreaking. Durham had been in and out of mental institutions for various personality disorders since he was a teenager, and after his attorney appealed the decision, the appellate judge used the case as an opportunity to overhaul the insanity defense. During the appeal, the judge declared the M'Naghten Rules "an entirely obsolete and misleading conception of the nature of insanity." In the ruling, the court stated that the accused isn’t criminally responsible if the crime was the product of a mental disease. The opinion of the court was hailed as a revolutionary step toward modernizing criminal justice for the mentally ill, modernizing the law to address the advancements in psychology and psychiatry. [[FN: Less than a decade later in 1962, the American Law Institute established yet another standard for insanity; the new ALI test stated that a person could not be held responsible if, at the time of the crime, they lacked “substantial capacity to either appreciate the wrongfulness” of their act at the time they committed.]] The ruling also meant that psychiatrists now wielded great power in American courtrooms, and could be brought in to give comprehensive tests to defendants to determine insanity or illness, and also be used as expert witnesses in the trial. The case of John Hinckley, Jr. was a kind of saturation point of this rapid ascent of psychiatrists in criminal courts.

In a country in which anywhere from 15 to 20 percent of the incarcerated population suffers from severe mental illness, it’s still unclear exactly where the line between those with mental afflictions who are held responsible for their crimes and those who are not truly is.

At the age of 20, John Hinckley, Jr. dropped out of Texas Tech University in 1975 and flew to California to pursue his dream of becoming a songwriter. But, lacking the confidence and contacts to make it in the music industry, he instead burrowed deeper into his own increasingly toxic fantasy world. In 1976, he saw Taxi Driver and became obsessed with it: the explosive misfit Travis Bickle, themes of alienation from a venal society, and most of all, 12-year-old prostitute Iris Steensma, played by Jodie Foster.

After stalking Foster for years (while she was studying at Yale, Hinckley moved to Connecticut and took a writing course there to be closer to her), he decided it was time to win her attention once and for all. Hinckley was going to assassinate the president.

On March 30, 1981, Hinckley attempted to kill President Ronald Reagan as he was leaving a Hilton in Washington, D.C., managing to fire six shots before the Secret Service wrestled him down. Not guilty by reason of insanity was his only chance at avoiding life imprisonment. The defense and the prosecution dispatched psychiatric teams to evaluate Hinckley, offer witness testimony, and enter exhaustive reports into evidence.

The most prominent expert witness for the defense, Dr. William Carpenter, believed Hinckley suffered from what he called "process schizophrenia." He testified that Hinckley's "fairly subtle disorders" during adolescence became more severe over time, eventually blossoming into the full-blown psychosis that drove him to an assassination attempt. Dr. Carpenter frequently pointed to Hinckley's pathological infatuation with Taxi Driver—the way he fashioned himself after Robert De Niro’s Bickle, traveled to New York City in search of prostitutes to "rescue," indulged in elaborate fantasies about Foster—as evidence of his schizophrenia diagnosis and slippage from reality.

Naturally, the prosecution's team of psychiatrists came back with a different set of diagnoses. Their leading psychiatrist, Park Dietz, diagnosed Hinckley with several personality disorders, including schizoid, narcissistic, and mixed personality disorder. Dietz found that Hinckley suffered from feelings of emptiness and boredom, identity issues, passive-aggressive behaviour, and a chronic aversion to work. After hearing Dietz's testimony, the D.C. press dubbed this constellation of traits "dementia suburbia."

It was easy for an outsider to see Hinckley as lazy, privileged, and petulant. But it wasn't just Dietz's occasionally harsh characterizations of Hinckley that set him apart from Carpenter. Dietz's diagnosis differed largely because it didn’t consolidate Hinckley's scattered, troublesome attributes into a larger narrative of psychosis. Hinckley was crazy, sure, but he wasn't crazy-crazy. The DSM-5 estimates that around 50 percent of the population has at least one mental disorder, but only 1 percent is schizophrenic. There was a big difference between having two or even three personality disorders and being schizophrenic, but for the prosecution, this distinction may not have been enough: it had to prove that the defendant was sane at the time of the crime. Between the defense’s expert witnesses, the battery of personality disorders, and Hinckley’s all-consuming erotomania for Foster, proving sanity was a tall order.

He never did show the typical signs of schizophrenia. He never had visual or auditory hallucinations, paranoia, or any of the devastating clinically negative symptoms, such as monosyllabic speech, or extreme apathy verging on catatonia. Schizophrenia is defined by a fairly specific set of symptoms, but the sheer density of the expert testimonies and criteria challenged the jurors, lacking knowledge of mental illness and susceptible to courtroom distortion. Interpreting the language of the ALI standard for insanity turned out to be wildly subjective. What constitutes "substantial" capacity? Is appreciating "the wrongfulness" of one's crime really critical to sanity?

Carpenter was dead-set on his diagnosis, though it wasn’t exactly shared: of the eight psychiatrists who evaluated Hinckley, he alone diagnosed schizophrenia. But despite a successful cross-examination of Carpenter by chief prosecutor Roger Adelman, Hinckley was found not guilty by reason of insanity.

Distinguishing between those who are mentally ill but still responsible for their crimes and those who are not became nearly impossible in the Hinckley trial. The deceptively hollow and therefore malleable ALI standard came undone: jurors were unconvinced that Hinckley was sane leading up to the assassination attempt, or that he was able to conform to the rule of law. But logically speaking, in order to establish insanity, you must first establish the existence of a severe mental illness. If this prerequisite is ignored, forensic psychiatrists can warp the narrative, depicting a “descent into madness” or even psychosis without ever proving genuine mental illness. Without a strong enough distinction between a mental illness capable of producing insanity and mere psychological instability, the insanity defense can be exploited for the wrong reasons.

This was exactly what happened in the Hinckley trial. In response to the public outcry against the verdict, congress passed the Insanity Defense Reform Act of 1984. Under the new provisions, the accused had to have been suffering from a severe mental illness, and the burden of proof shifted to the defense, which had to prove that the defendant was legally insane at the time of the crime.

Since Hinckley, the insanity defense has become subject to the imagination and whims of media—an escape hatch for cunning sociopaths play-acting crazy, the macabre final destination for serial killers who embodied pure evil. The legacy of the Hinckley trial represents everything that is imperfect about the insanity defense: the undue power of forensic psychiatrists, the blurred lines of sanity, and sensationalistic portrayals of what it means to be legally insane.


After her husband left for work on June 20, 2001, Andrea Yates, a former nurse, drew a bath in her Houston, Texas, home and drowned all five of her children. She laid three back in bed afterward, leaving six-month-old Mary floating in her brother’s arms in the tub. She then called her husband, repeating, "It's time," over and over. Yates had been suffering from serious psychiatric problems for years. Shortly after the birth of her first son in 1994, she started having visions of a knife stabbing someone. In 1999, she attempted suicide by swallowing 40 pills of the antidepressant Trazodone. Shortly after being discharged from the hospital, the knife-wielding phantom returned. She heard voices telling her to "Get a knife! Get a knife!" One day her husband found her staring in the bathroom mirror with a knife to her neck, imploring him to "Let me do it."

By June 2001, Yates had attempted suicide at least twice, and had endured multiple breakdowns and hospitalizations. She was diagnosed with postpartum depression and postpartum psychosis. Ignoring the counsel of Yates’ psychiatrist, her husband insisted on continuing to have children after the psychotic episodes, exacerbating her postpartum symptoms.

Her plight was further complicated by religious zealotry: Yates felt a deranged, merciless form of Christian guilt. Her husband would later tell Time writer Timothy Roche that his wife's story came down to two things: "Bible and brain."

The legacy of the Hinckley trial represents everything that is imperfect about the insanity defense: the undue power of forensic psychiatrists, the blurred lines of sanity, and sensationalistic portrayals of what it means to be legally insane.

During the trial, psychiatrists for the defense pointed out that Yates was suffering from severe postpartum depression with psychotic features at the time of the murder. And who could argue? She believed that killing her children was the only way she could save them from Satan, salvaging their eternal souls. While in prison, she told a psychiatrist that Satan spoke to her and her children through morning cartoons, and asked the doctors if they could shave “666” into her head. If the insanity defense wasn’t going to win in this case, then why have it at all?

Twenty years after first establishing his reputation in the Hinckley case, Park Dietz was yet again testifying on behalf of the prosecution. He didn’t try to dissuade the jury of Yates' mental illness, but rather argued that her act was premeditated and therefore not exclusively the product of her psychosis. He did this by explaining how Yates had planned the murder after seeing an episode of Law & Order, in which a mother drowns her children. Dietz's tactic worked, and Yates was found guilty of murder.

Except the episode to which Dietz referred, it turned out, didn’t exist. The revelation came from one-time Law & Order writer Suzanne O'Malley, who was covering the trial for Oprah magazine and reported the false testimony to Yates’ attorney. Although the scoop came too late to save Yates from the original guilty verdict, it led to a reversal of the convictions in 2005, a new trial, and, finally, a 2006 verdict of not guilty by reason of insanity. Still, it's a wonder that Yates was ever convicted in the first place—she’d already been diagnosed with postpartum psychosis, a potentially severe mental illness that was clearly an overpowering force in her life. But two obstacles prevented her from winning a not guilty by reason of insanity plea in the first trial.

First, in order to prove insanity under Texas law, the defense has to show that the defendant was unable to tell the difference between right and wrong. This particular criterion is wildly flawed: Yates may have known how others perceived right from wrong, and thus planned her crime to prevent them from stopping her. Plenty of mentally ill adults without developmental disabilities still recognize conventional definitions of “right and wrong.” In the worst cases, their illness overpowers those moral laws; their value judgments change.

Second, the cogency of Dietz’s testimony trumped the facts of Yates’ illness. In the courtroom, narrative coherence often becomes more important than reality. In his essay "The Legal and the Literary," psychologist Jerome Bruner explains how the courts must "be seen as fair and disinterested, capable of rising above the self-serving and adversarial narratives by which cases are presented." But this is not always possible. Sometimes aesthetics triumph over truth, and an exquisite story can defeat a muddled one despite where the facts lie.

Admittedly, part of the challenge with cases featuring the insanity defense is the problem of trying to dichotomize the mentally fit from the mentally ill. Severe, paralyzing and often baleful mental illness is real, and the law should protect those who suffer at the hands of it. But do sanity and insanity exist on a spectrum, or in a binary? How do we draw a line between those who should be held responsible for their crimes, and those who couldn’t have helped themselves?


Colorado’s insanity defense law is unique: unlike most states, the burden of proof remains on the prosecution to prove sanity at the time of the crime.

James Holmes will no doubt be diagnosed with some variety of mental disorders by the phalanx of psychiatrists that will testify during his trial. It will be up to the jurors to decide whether his mental illness was severe enough to obliterate his moral compass or his ability to comprehend the consequences of his actions. But the narrative of his gradual descent into disaffection, reclusion, and mania is already in place, as is the inexorable public enmity for a man who erased a dozen lives.

Four months before the shooting, in March 2012, Holmes told a University of Colorado classmate that he wanted to kill people “when his life was over.” It’s easy to envision a scenario in which prosecutors use this as evidence that his rampage was a premeditated act, but what about the conundrum of the phrasing of “when his life was over”? Surely it offers some insight into his mental state: irrational, sharing plans to commit murder after his own death—potential proof of both deliberation and illness in a single quote, buried among reams of court records. It is, of course, just one piece of evidence among possible hundreds, all to be presented as objective truth by both sides—between whom are the jurors, who are about to face the challenge that is looking for sanity and insanity in a courtroom that warps them both.

Mike Mariani is a writer and educator based in Hoboken, NJ. His work has appeared in LA Review of Books, Pacific Standard, The Atlantic, and This Land.