A version of this article originally appeared on the Trace.
On November 7, 2016, Esteban Santiago walked into the FBI field office in downtown Anchorage, Alaska, holding his newborn child. The 26-year-old Army National Guard veteran told the agents who greeted him that his mind was being controlled by the CIA.
Special Agent in Charge Marlin Ritzman said Santiago was "agitated, incoherent, and [making] disjointed statements." Ritzman added that Santiago said that "he did not wish to harm anyone," but his behavior prompted agents to contact local police.
Chief Chris Tolley of the Anchorage police has described the incident as a "mental health crisis."
Santiago had a pistol magazine on him and the unloaded weapon in his car. Earlier in the year, he had attempted to strangle his girlfriend in an episode that landed him in a deferred prosecution program, authorities said.
Anchorage police seized the firearm and took Santiago to a mental health facility.
Despite the erratic behavior he had displayed, Santiago would soon be reunited with his gun. One day and one month later, he went to police headquarters to collect his firearm.
On January 6, Santiago checked the same 9mm handgun on a flight from Anchorage to Fort Lauderdale, Florida. After landing, he allegedly retrieved the weapon from his baggage, loaded it in an airport bathroom, returned to the baggage claim area, and opened fire. Apparently aiming for the heads of his victims, he shot 11 people, killing five.
Following the shooting, Broward County sheriff Scott Israel, whose officers responded to the scene of the attack, was among many to question the efficacy of American laws regarding psychiatric illness and guns.
"People who are suffering from mental illness should not be allowed, in my opinion, to purchase or have firearms at any time," he told a Miami news station. "Enough is enough."
But unless facts emerge suggesting otherwise, there was nothing in the existing statutes to prevent Santiago from getting his gun back. Under federal policy, one of the few ways for a person to be judged psychologically incompetent to possess a firearm kicks in only when a court orders that person hospitalized for psychiatric care against his or her will.
"As far as I know, this is not somebody that would have been prohibited based on the information that [authorities in Alaska] have," Karen Loeffler, the US attorney for the District of Alaska, said at a news conference.
"Gun control in our country isn't really gun control. It's people control," Jeffrey Swanson, a professor of psychiatry and behavioral sciences at Duke University School of Medicine, told the Trace. "And how we do that is complicated."
Here is a primer on how people are determined too mentally unfit to own a gun, how such determinations are enforced, and the flaws that experts see in the current system.
How does the government decide who is too mentally ill to have a gun?
The standard in place was established by the 1968 Gun Control Act, which set a high bar. One way to be disqualified from possessing a gun is to have been involuntarily committed to mental health treatment. The mental health ban also applies to prospective firearms owners "adjudicated as a mental defective"—an antiquated term to describe individuals found unfit to stand trial, incompetent to take care of their own affairs, or a danger to themselves or others.
But the law as applied isn't at all clear-cut. States have enacted a mix of policies that seek to define what qualifies as mental health treatment, and the length of time that a firearm ban must stay in place before a person may appeal to have it reversed.
This is where the fine print comes in?
In a handful of states, including Wisconsin, persons committed by law enforcement authorities to an emergency detention—commonly the longest allowed without a ruling by a judge—have their guns temporarily taken away. In slightly less than half of the country, the definition of involuntary commitment is expanded to include mandated outpatient programs, a step down from hospitalization. Other states require that individuals be hospitalized for a minimum length of time before their gun rights can be stripped. In Washington, for example, a person has to be involuntarily committed for more than two weeks to be prohibited from possessing a gun.
States also have myriad and differing rules for how individuals subject to firearms bans can petition to restore their gun rights.
What about people who voluntarily commit themselves for psychiatric treatment?
In most states, a person who voluntarily enters inpatient treatment is not barred from purchasing a gun, although there are a few exceptions. For example, Connecticut prohibits people who check themselves in for mental health care from possessing or purchasing firearms for six months after release. Illinois requires former voluntary psychiatric patients to be certified as no longer a threat.
How do gun sellers know if someone has a history of mental illness?
Licensed gun dealers are required to query the FBI's federal background check system—the National Instant Criminal Background Check System, or NICS—to see if a would-be customer is banned from purchasing a firearm. If a buyer's name is listed among those with disqualifying mental health records, the dealer is supposed to refuse the sale.
In all but 19 states, private sales do not necessitate a background check, and therefore do not involve a mental health screening.
Check out our 2012 documentary about gun culture in Florida.
So the FBI keeps the names of everyone barred from buying a gun under federal law?
No—the system only contains the records forwarded to it by officials farther down the chain. Federal law doesn't require state healthcare officials to submit records to NICS. And while 43 states have their own laws for forwarding psychiatric records to federal background check databases, the comprehensiveness of those requirements varies widely.
A glaring consequence of those records gaps can be found in the case of the Virginia Tech gunman, Seung-Hui Cho, who should have been barred from purchasing the gun he used in his 2007 rampage. A Virginia court had declared Cho a danger to himself two years before the massacre, and mandated that he seek psychiatric treatment. But his mental health records were never reported to NICS, and Cho was able to buy the guns he used to kill 32 people and wound 17. An investigative panel ordered by then-governor Tim Kaine in the wake of the shooting found that "the system failed for lack of resources, incorrect interpretation of privacy laws, and passivity.
The Virginia Tech killings spurred Congress to pass the NICS Improvement Act of 2008, which gave healthcare providers financial incentives to report patient mental health records to NICS (before the bill, only 22 states were voluntarily doing so). But funding was also contingent on states creating "relief from disability" programs, which allow people to petition to have their gun rights restored. As of December 2015, states had submitted nearly 4 million mental health records to the background check system.
But compliance is inconsistent. While Pennsylvania has submitted 756,952 records to NICS, four states have submitted fewer than 100, which means that even if Santiago's history had met the criteria for involuntary commitment, his record might not have been in the database, anyway.
Does the existing system at least flag the people most likely to carry out violence?
Experts have their doubts.
Anger-management issues and impulsive-aggressive behavior are highly correlated with gun violence, as are common mental health issues such as PTSD and alcoholism, according to Swanson, the Duke professor. People with such conditions are rarely hospitalized, and thus don't fall under the federal definition of dangerousness under the 1968 law.
Swanson authored an analysis estimating that about one in every ten American adults who has a problem with anger and impulsive-aggressive behavior also has access to firearms. The study suggests that firearm violence might be better prevented if policies restricted gun access for Americans demonstrating a pattern of uncontrolled angry behavior.
Only a few states—including Connecticut, Indiana, California, and Washington—have those kinds of measures in place. The California version, dubbed a "gun violence restraining order" and implemented in 2016, enables friends and family members to have a loved one's gun seized for a defined period of time if they believe he or she poses a threat to themselves or others, even if he or she doesn't meet the criteria for involuntary commitment.
Swanson argues that the federal government's definition of mental illness is"too broad and also too narrow." Many people fall under the government's definition of mentally ill who are very unlikely to ever be violent—and in fact are much more likely to be the victims of violence themselves, research shows.
On the other hand, the definition misses many whose conditions place them at elevated risk of lashing out, perhaps lethally, if they have access to firearms.
Along with the Fort Lauderdale gunman, a number of recent mass shooters clearly suffered from mental illnesses but had never been involuntarily committed, including the perpetrators of the attack that wounded former congresswoman Gabby Giffords, the Aurora movie theater shooting, and the Washington Navy Yard and Santa Barbara rampages.