His five years as a student at Sandy Hook Elementary school were uneventful. In middle school, his teachers described him as having a “positive attitude,” and being “eager to succeed.” And even when things began to change for Adam Lanza in the eighth grade, when his strange behavior prompted his mother to drive him to the emergency room for an evaluation, the 13-year-old still seemed relatively normal. No one would have guessed that, seven years later, Lanza would return to Sandy Hook to carry out what is now one of the most well-known rampage shootings in history.

Social scientists who have tried to explain what provokes mass shooters like Lanza have failed. Predicting a rare event such as a mass shooting is a difficult task. And preventing one—something mental health professionals have been recently charged with—is even harder. The problem is that while many shooters show signs of mental illness years before they commit their crimes (i.e. Lanza’s episode of strange behavior that prompted his mother to drive him to the emergency room), most mentally ill people do not become shooters. In fact, those with mental illness are more frequently victims of violence than perpetrators of it.

Investing in increased access to mental health treatment is critical not because it would prevent mass shootings but because, conversely, it would help protect people with mental illness from others’ violence and from suicide. While only about four percent of community violence is attributed to the mentally ill, over 90 percent of people who commit suicide have mental illness.

The Centers for Disease Control and Prevention recently released its annual report on violent death in America. In 2010, the most recent year for which it tabulated data, a total of 15,781 violent events led to 16,186 deaths. Most of them—63 percent—were suicides.

It is tempting to say that we can rearrange the pieces of a shooter’s past to form a set of clues leading to the atrocity. Indeed, many reporters who covered the atrocity in Newtown suggested that Lanza’s teachers, family and friends should have seen the warning signs; should have acted before it was too late. Journalists who have investigated Adam Lanza’s past wrote of neighborhood rumors that Lanza’s mother had spoken to a local religious official about sending her son for psychological help; some describe a sketch Lanza allegedly drew depicting people being shot. But a thorough criminal investigation of the family’s home found only a series of harried emails Lanza’s mother had written to family members in which she wrote of being afraid her son shared the “genetic” problems from which she suffered.

Advocates, politicians and most recently the Obama Administration have argued that the way to stop rampage shootings is to increase access to mental health services. The only reason no one spotted Lanza, they say, is because he was not being seen by a mental health professional. The story of Aurora shooter James Eagan Holmes, who had contact with three medical professionals, should firmly disabuse any of that notion. For although he showed signs of mental anguish (and was seeking help), none of his family, friends, or mental health professionals identified a single clear sign that he would open fire on a movie theater filled with innocent people, killing 12 and wounding 70. “In retrospect we tend to make the link much clearer than it appears looking forward,” says University of Pittsburgh psychiatry professor Edward Mulvey. “Based on our work so far, we are not going to get a whole lot better at predicting whether or not a particular person is going to do this at a particular time.” Experts say they lack the tools to predict future rampage shootings. In fact, they say, they don’t even know what such tools—if they exist at all—would look like. “It would be great if we just had a checklist we could go down and say, ‘Well, he did this and this and this,’ but we don’t,” says Case Western Reserve University professor of applied social sciences Daniel Flannery.

While the idea that we would be able to pick out potential rampage shooters is troubling, there are other factors, too, that make doing so nearly impossible. First, most rampage shooters commit their crimes between the ages of 18 and 25, the period when most behavioral changes occur and the time when mental illness tends to materialize. “A lot of adolescents and adults are dealing with these issues. Just because they are doing these things doesn’t mean they’re going to engage in a horrible act,” says Mulvey. Second, mass shootings remain relatively rare: the likelihood of dying in a rampage shooting in 2012, the deadliest year for mass shootings in a decade, was one in 3 million.

Implicit in the notion that mental health professionals should be able to identify potential mass shooters is the idea that people with mental illness are more likely to kill than those without mental health issues. Statistics say otherwise. In a 2001 study of 1,200 newly admitted prisoners in which two-thirds had either a major mental or substance abuse disorder, Queens University professor of community health Heather Stuart found that prisoners with a mental disorder not related to substance abuse accounted for three percent of violent offenses. This finding supports a 1994 study by Duke University professor of psychiatry Jeffrey Swanson in which he found the rate of violent events attributable to people with mental illness was about four percent. Stuart and Swanson have identified a host of factors other that mental illness that are far more accurate predictors of violence, including substance abuse, which she says has an association rate of about 34 percent. “If we cured all mental illness tomorrow,” says Swanson, “96 percent of our violence problems would not be solved.”

The real reason we should support mental health services is not to prevent violence against others, but to prevent stigmatization and suicide. According to data from the Centers for Disease Control and Prevention, suicide has increased each year since 2000. Ninety percent of those who commit suicide have mental illness. Media portrayals that focus solely on the mental illness of a mass shooter threaten to do just the opposite. In a study of people’s responses to typical media coverage of mass shootings, Johns Hopkins School of Public Health professor Emma McGinty found that reading coverage in which a shooter was described as mentally ill heightened people’s negative attitudes towards those with mental illness. Although nearly all news media depictions of mass shootings highlight the shooter’s mental illness, they fail to include some very important facts, McGinty says. “News stories very rarely mention that most people with serious mental illness are not violent. They also very rarely mention that over 95 percent of gun violence does not have anything to do with mental illness.”

Without their weapons, shooters Lanza and Holmes would have been powerless to act. Similarly, the nearly 50 percent of the Americans who commit suicide every year would be unable to do so without access to a handgun. While Flannery, Mulvey, Stuart and McGinty differ in their opinions about how to address mental health services, they all agree on one thing: access to guns increases the likelihood of violence. “The more accessible firearms are the more likely a person committed to doing an act will do it,” Flannery says. Perhaps the real solution to decreasing violence in the community—both in cases where people harm others or themselves—is reducing access to guns.