Keeping guns away from people with mental illness is a complex issue WASHINGTON - For years, federal and state governments have struggled to build a background check system that can keep guns out of the hands of mentally troubled people. Monday's mass shooting at the Navy Yard shows that goal remains elusive. The National Instant Criminal Background Check System, or NICS, run by the FBI, is supposed to prevent gun sales to people with serious mental illness, as well as to convicted criminals, fugitives and domestic violence offenders. Despite the system's name, not all the people it flags have been accused of wrongdoing. President Obama, lawmakers and gun-control advocates have pushed hard to persuade states to turn over more of their mental health records to the federal system. But the fix isn't that simple. Because of problems in the mental health system and NICS' definition of mental illness, the national background check system has proved to be a haphazard way of trying to identify who might be too dangerous to own a gun. Most mentally ill people - including Aaron Alexis, the Navy Yard shooter who apparently showed signs of psychosis - never get treatment or aren't recognized as being in crisis. Only a small fraction of people with mental illness meet the federal standards for inclusion in the gun database. Those standards include a court ruling of insanity. Most, however, enter the database after they have been involuntarily committed to a psychiatric hospital. Further, most people who are involuntarily hospitalized - typically under a 72-hour hold for observation - aren't included in the database, because they cases never received a formal mental health evaluation by a judge. The result is a system that misses many people who are at risk of harming themselves or others, while it sweeps in thousands of others who are no longer dangerous or never were in the first place. "We set the bar pretty high before we take away someone's gun rights," said Mark Glaze, director of Mayors Against Illegal Guns, which is fighting for an improved background check system. The pro-gun lobby and many mental health advocates would oppose more expansive rules, he noted, saying, "It's hard to imagine we are going to lower the bar on that." Some states use tougher standards than the federal rules to try to keep guns out of the hands of people with mental illness. California bans someone from buying a gun for five years after a 72-hour commitment. Even people who check themselves into a hospital for psychiatric treatment can lose their ability to buy a gun. But California doesn't send those names to the federal system; state officials decided their mental health records didn't meet the federal guidelines. Of the 1.3 million such records in its state database, California has sent only 400,000 to NICS. That means someone with a recent 72-hour hospitalization would be banned from buying a gun in California but could clear a background check in another state. In 2006, former postal worker Jennifer Sanmarco returned to her old post office in Goleta and shot six people, then killed herself. Sanmarco had spent three days in a Ventura hospital after a history of bizarre and paranoid behavior - and couldn't legally buy a gun in California. But she had no trouble passing a background check when she bought her gun at a New Mexico pawn shop. At the time, California had not submitted any records to NICS. The Navy Yard shooting points to another problem: Like Alexis, most people who suffer from apparent mental illness are never treated. Even though police who encountered Alexis in Rhode Island worried about his delusions, there are no reports that he was hospitalized. He twice went to Veterans Affairs hospitals complaining of insomnia. Doctors asked him whether he was depressed or had thoughts of harming himself or others; he said no. Even if those doctors had thought he might be dangerous, it's not clear they would have told anyone. VA rules prohibit the disclosure of medical records for employee background checks. And the VA also doesn't disclose most records to NICS unless someone in law enforcement asks for a specific record. The exception is when a veteran is found incompetent to handle his or her affairs. In falling outside the bounds of background check standards, Alexis had something in common with perpetrators of other mass slayings. James Holmes, the gunman in the Aurora, Colo., movie theater shootings in 2012, passed a background check. So did Jared Loughner, who in 2011 killed six people in Tucson and wounded 13 others, including Gabrielle Giffords, who was then a congresswoman. Adam Lanza, the Newtown, Conn., elementary school shooter, got his guns at home, but he would not have had trouble passing a check either. In fact, in 43 mass shootings over the last four years, none of the shooters was prohibited for mental health reasons from possessing a gun under federal law, according to a survey published by Mayors Against Illegal Guns. None had been involuntarily committed.