If you wanted to invent an avatar to represent the type of person who should not have easy access to firearms, you might come up with someone like Heon “Hank” Yoo.

In 2013, after threatening to shoot his resident counselor at Rutgers University, the then-19-year-old Yoo was committed to a New Jersey psychiatric hospital, where he was diagnosed with “aggressive homicidal ideation and explosive personality disorder.” A year later a friend was alarmed enough at Yoo’s behavior at a shooting range to alert police. He “would shoot at the head of the target every time, even though range policy specifically prohibited such contact,” he reported. Even after warnings, Yoo “continued to shoot at the head.”

Yoo was admitted to a psychiatric clinic again in 2015 “after repetitive disruptions [and] homicidal threats.” Several colleges banned him from their campuses. He was twice rejected for military service because of his unstable mental health. Online, he became known as the “Asian Nazi” for his racist rants and threats of violence against blacks and Jews.

Yet the Texas Department of Public Safety issued Yoo a license to carry a handgun.

The hospitalizations should have barred Yoo from Texas licensure; federal law prohibits anyone who has been involuntarily committed to a psychiatric facility from buying or possessing a gun. The public safety agency insists it conducts thorough background checks to vet applicants, so it’s unclear how it missed the red flags fluttering in Yoo’s wake. The department did not respond to questions.

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Yoo’s case represents a facet of the so-called relinquishment gap: the regulatory lapses that occur between the time authorities determine a person shouldn’t have guns, and when they actually disarm him. While there is no evidence a large number of gun owners slip through the public safety department’s background checks — and as a group Texas handgun licensees rarely commit crimes — the agency’s error with Yoo demonstrates how, when guns are involved, even the occasional snafu can have long-lasting consequences as officials navigate a tangle of laws to undo it.

Texas’s carry permit holders can purchase guns without undergoing the required federal background check - the assumption being state regulators have already scrubbed the applicant’s past. With his record of mental instability cloaked by his Texas license, Yoo was able to easily accumulate weapons he should have been banned from having, including handguns and assault-style rifles.

Later, when the public safety agency realized its error and moved to take away his license, the process took months — during which time Yoo continued using the wrongly issued permit to buy more guns. Even when it finally revoked the license, the Department of Public Safety merely mailed Yoo a letter asking him to send it back. Instead, he used it to buy even more guns.

The mistake compounded and spread as Yoo used the weapons state regulators allowed him to acquire to menace and threaten East Texas residents over nearly two years. “My opinion is that he literally held the university hostage for two months with his disruptive behavior,” University of Texas-Tyler Police Chief Mike Medders said.

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In one 2017 incident, Smith County officials tried to have Yoo committed at a psychiatric hospital after he’d threatened to kill people. But they couldn’t find an open bed and so had to release him. “Just as an FYI, we returned Yoo’s guns to him this morning,” a Texas Ranger wrote in an email. It is not clear why the agency returned firearms to a person prohibited from having them.

“Thank you for letting us know,” a prosecutor replied. “I’m praying everyone will stay safe.”

The system works — at first

Since passage of the Gun Control Act of 1968, federal law has prohibited people “adjudicated as a mental defective” or who have “been committed to a mental institution” from buying or possessing firearms. Mental health orders are issued by thousands of local courts, however, so keeping track of them hasn’t been simple. In 1994, the Brady Act created the National Instant Criminal Background Check System — NICS — as a one-stop clearinghouse for firearms dealers to check before making a sale.

Even then, NICS must rely on states voluntarily entering their local criminal and mental health records. Many were slow to sign on. By 2007, after Seung-Hui Cho was able to buy the guns he used to kill 32 at Virginia Tech despite a history of mental illness, studies showed that nearly half of the states hadn’t been submitting their records to NICS.

Congress and states have since enacted measures to gain greater compliance. In 2009, Texas began requiring local courts to report their criminal and mental health adjudications to the Department of Public Safety, which funnels them to the FBI. The state has sent 300,000 mental health notifications to NICS, ranking it as one of the more compliant in the country, according to fixnics.org, a firearm industry-funded organization dedicated to improving the background check system.

New Jersey is ranked second-best among states in NICS compliance. Records show local court officials promptly entered Yoo’s two disqualifying psychiatric hospitalizations into the database.

Initially, the system worked as intended. In January 2016, Yoo, who recently had moved to Texas, tried to buy a gun at a Grandview store. But the dealer’s NICS check returned “denied” and he walked out empty-handed.

A month later, he applied to the Texas Department of Public Safety for a license to carry a handgun.

Threats and racist rants

Although federal laws typically are used to prevent people with a mental health history from acquiring guns, Texas law also bars handgun licensure to anyone with a history of psychiatric hospitalization or a diagnosis of several specific disorders, including bipolar and schizophrenia. Yet the state relies on applicants self-interpreting and truthfully reporting their own medical histories.

In his application, Yoo denied having received psychiatric treatment. In later court testimony, he explained he didn’t think he had a mental illness; and that he didn’t consider being ordered into treatment a commitment.

Numbers released by the Texas Department of Public Safety show handgun license denials from self-reported psychiatric conditions are rare. Over the past five years, the agency has issued 1.47 million handgun carry licenses and rejected 7,229 applicants. Of those, fewer than 200 were denied for mental health reasons — a number that includes self-reported drug treatment within five years of the application, which can also be disqualifying.

DPS said it also runs all applicants through the NICS database before issuing a license. Nevertheless, on May 24, 2016, it granted Yoo permission to publicly carry handguns.

Records show he quickly put it to use. In June, police in Prosper, north of Dallas, were called to a grocery store where a man reportedly was threatening to shoot people. Yoo’s truck had a Confederate flag hanging off it. When police asked for his ID, he showed them his handgun permit. He was carrying a .45 semiautomatic handgun; an AR-15 assault-style rifle and ammunition were inside the truck.

Yoo admitted stating “Black Lives Matter” should be labeled a terrorist organization “and that the federal government and the U.S. military should be able to kill them all,” according to the police report. He’d also “made statements about his hatred of individuals who practice Islam and Judaism.” But officers determined that he had not threatened anyone specifically, so no crime had been committed.

Two months later, police were called to the University of North Texas campus, in Denton, where Yoo was waving a Confederate flag and arguing with students. He acknowledged he was carrying a gun. “I feel threatened,” a student told the North Texas Daily student newspaper. “And I shouldn’t.”

But campus-carry recently had been legalized by the legislature, and police determined Yoo was a Texas license holder, so there was nothing they could do.

Confirmation that Yoo was not legally permitted to possess the firearms came on September 13, as he tried to buy a Glock handgun from Superior Firearms, in south Tyler. When Yoo presented his Texas carry license at checkout the address did not match his driver’s license, so the store decided to run his name through NICS. The database again returned a “denied” notification.

“That’s when he went off,” salesman Bailey Averitt recalled, “yelling that the U.S. should have sided with Hitler” and killed all the blacks and Jews.

Gun buying spree not legal — but successful

Even after learning about Yoo’s disqualifying psychiatric history, the public safety department moved slowly.

During his run-in with them, Yoo had told Prosper police he was rejected for military service because of his mental health history. The department notified the Department of Public Safety, which opened an investigation into his handgun carry license.

To guide its medical-related decisions, the agency relies on an obscure panel called the Medical Advisory Board. Three doctors review each case and render a opinion.

On Sept. 15, 2016, the panel concluded Yoo’s mental illness made him “incapable of exercising sound judgment,” thus ineligible for a handgun license. DPS ordered him to surrender his license unless he wanted to challenge the decision.

Yoo did. Medical board appeals are heard by local judges. Records at Smith County Justice of the Peace No. 2 show it took DPS four more months to file the paperwork. In the meantime, Yoo continued using the license.

In November, records show he used it to purchase a handgun and an M&P 15 assault-style rifle.

On December 19 he used it to buy another assault rifle.

On December 21 he purchased a .40 caliber handgun.

On Jan. 9, 2017, he bought another assault-style rifle.

Yoo’s Medical Advisory Board hearing was on March 15, 2017. He didn’t show up, and Judge Gary Alfred quickly upheld the panel’s decision to revoke his handgun license.

Even then, the public safety agency’s only action was to send Yoo a letter ordering him to relinquish the license. Months later Yoo was still able to use the invalid Texas license to skip federal background checks. Records show that in November 2017 he bought two shotguns at a Tyler pawnshop.

“He didn’t purchase them legally,” said Frank Coan of the U.S. Attorney’s Tyler office. But, “he purchased them successfully.”

“He may turn violent at any moment”

As Yoo accumulated guns, “There was an escalation of incidents,” Coan said.

It’s unclear how much of what he said was intended only as provocation. But his menacing language and license to carry meant police had to take him seriously.

Between May 2016 and early 2018, Tyler police generated nearly two dozen reports on Yoo. Five local stores and apartments asked police to write an order banning him from their premises.

In October 2016 a Walmart shopper told Tyler police an Asian man had told her he wanted to start killing police officers. The officer recognized Yoo from surveillance footage, writing: He “is known to carry a firearm.” A week later, Target shoppers reported a man carrying a handgun and wearing a Confederate flag bandanna over his face said he wanted to kill all the black people in the store.

In December, Yoo was charged with aggravated assault with a deadly weapon after allegedly pointing a gun at an African-American man. A handgun, shotgun, semi-automatic rifle and body armor were in his car. The charges were eventually dropped when witnesses gave inconsistent statements, said Jason Parrish, Yoo’s attorney.

After Yoo enrolled at the University of Texas-Tyler, administrators fielded more than a dozen complaints and produced two dozen “Behavioral Intervention Reports.”

Despite the confrontations, records show authorities struggled to stop him. In late 2017, Texas Rangers investigating Yoo’s mistakenly issued handgun license interviewed several witnesses who reported hearing Yoo vow “he was going to Washington to kill blacks and Jews.”

Called into their Tyler office for an interview, Yoo wore a suit with American flag cufflinks. In the police report, the Ranger noted he “makes people nervous” by dressing up in World War II uniforms and carrying around Hitler’s manifesto, “Mein Kampf.”

“Hank has several unorthodox ideas,” the Ranger added, “such as all single mothers should be shot in the back of the head.”

Yoo was taken in for a psychiatric evaluation. According to court records, “medical professionals deemed him harmful to others” and the local crisis center recommended Yoo be involuntarily committed.

But according to emails from the Smith County District Attorney’s office obtained under an open records request, “no state funded beds were available,” and the emergency room said he could no longer stay there. Yoo was released and his guns returned.

“Based on the current threat,” an assistant prosecutor wrote, “it may be in the interest of community safety” to have a deputy check up on Yoo.

By early 2018 the FBI had fielded “numerous complaints…concerning statements on both social media and in person as well as his behavior in public places,” according to a police report. On April 6, 2018, nearly two years after the Department of Public Safety mistakenly gave Yoo a license to buy and carry guns, Tyler police and agents for the Bureau of Alcohol, Tobacco, Firearms and Explosives gathered outside his apartment. “Investigators were aware of Yoo’s mental instability and the risk that he may turn violent at any moment,” so an officer pretending to be the building manager asked Yoo to come fill out some parking documents.

Charged with the technicality of lying on his firearm purchase forms about his nationality — although he is a legal resident, Yoo stated he was a U.S. citizen — Yoo’s trial, in which he represented himself, lasted three days last November. A month ago, he was sentenced to eight years in federal prison.

“These situations often end badly,” U.S. Attorney Joseph D. Brown said in a statement. “It was good that law enforcement worked together to get him off the streets as soon as they did.”