After the Tucson shooting spree that killed six people and gravely wounded Rep. Gabrielle Giffords (D-Ariz.), the psychiatrist E. Fuller Torrey wrote in The Wall Street Journal that such crimes are “the inevitable outcome of five decades of failed mental-health policies.” Syndicated columnist Mona Charen complained about “laws that require proof of dangerousness before a person can be involuntarily subjected to treatment,” which “make it exceedingly difficult to stop a crazed gunman before his murderous spree.” On The New Republic’s website, University of Maryland political scientist William Galston warned that “the rights-based hyper-individualism of our laws governing mental illness is endangering the security of our community and the functioning of our democracy.”

These and many other critics argue that innocent people could be saved if it were easier to imprison dangerous lunatics like Jared Lee Loughner before they commit crimes. But the champions of involuntary psychiatric treatment rarely consider the innocent people who would be stripped of their freedom and forced to take antipsychotic drugs if the government were allowed to lock up potential Loughners based on little more than their wacky beliefs and off-putting behavior.

In the 1975 case O’Connor v. Donaldson, the Supreme Court ruled that “a State cannot constitutionally confine…a nondangerous individual who is capable of surviving safely in freedom.” Galston says that was a mistake. He argues that “the law should no longer require, as a condition of involuntary incarceration, that seriously disturbed individuals constitute a danger to themselves or others.” Instead, “a delusional loss of contact with reality should be enough to trigger a process that starts with multiple offers of voluntary assistance and ends with involuntary treatment, including commitment if necessary.” To enforce this new standard, “those who acquire credible evidence of an individual’s mental disturbance”—including “parents, school authorities, and other involved parties”—“should be required to report it to both law enforcement authorities and the courts,” under penalties “tough enough to ensure compliance.”

In short, Galston wants a system that compels Americans to monitor their odd relatives, friends, neighbors, students, and employees, reporting them to the authorities when their strange ideas escalate into “a delusional loss of contact with reality.” That distinction may prove hard to draw. The evidence of Loughner’s mental illness, the “warning signs” that pundits said showed he was dangerous, consisted mainly of the eccentric opinions he expressed in college classes, online discussion threads, YouTube videos, and conversations with friends. Many of the things Loughner said on subjects such as grammar, mathematics, monetary policy, and dreams were inscrutable or demonstrably false. But if that were enough to signal a break with reality justifying involuntary commitment, our mental hospitals would be overrun.

The fuzzy line between Loughner’s opinions and his “mental disturbance” is apparent in a remark one of his friends made to The New York Times: “He was a nihilist and loves causing chaos, and that is probably why he did the shooting, along with the fact he was sick in the head.” Was Loughner’s nihilism a symptom of his illness, a cause of it, or an independent motivation for his crime? 

As difficult as such matters are to disentangle after the fact, it is even harder to say ahead of time which of the country’s many oddballs and malcontents will convert bizarre ideas into homicidal actions. In retrospect, every strange thing Loughner did or said marked him as a dangerous madman, including not just overtly crazy stuff like his video linking Pima Community College to genocide but borderline behavior such as singing to himself, talking out of turn, pestering teachers about grades, smiling and laughing inappropriately, and making weird comments in class. But it is not hard to see why administrators and police officers might have considered him a nuisance rather than a menace.

Even among people diagnosed as schizophrenics, Torrey says, only 10 percent ever become violent. So assuming that Loughner qualifies for that label, a policy of detaining people with similar symptoms would sweep up nine harmless individuals for each future criminal. 

Although they are routinely called upon to say whether people pose a danger to themselves or others, psychiatrists are notoriously bad at it. “Over thirty years of commentary, judicial opinion, and scientific review argue that predictions of danger lack scientific rigor,” notes University of Georgia law professor Alexander Scherr in a 2003 Hastings Law Journal article. “Scientific studies indicate that some predictions do little better than chance or lay speculation, and even the best predictions leave substantial room for error about individual cases. The sharpest critique finds that mental health professionals perform no better than chance at predicting violence, and perhaps perform even worse.”

The current system of involuntary commitment rests on predictions of dangerousness that are appallingly inaccurate. Abolishing the requirement of dangerousness would avoid that embarrassment at the cost of imprisoning even more people who pose no threat to others. 

Senior Editor Jacob Sullum (jsullum@reason.com) is a nationally syndicated columnist.