Identifying and stopping a likely mass shooter: A case study

AUSTIN, TEX. – While the media relentlessly reports on every mass shooting that occurs, the public hears less often about the shootings that never happened – because people were paying attention and taking action, according to James L. Knoll, IV, MD, director of forensic psychiatry at the State University of New York, Syracuse.

“We’ve learned a lot about risk factors [for mass shootings], we’ve learned a lot about associations and correlations, and it’s gotten us so far,” Dr. Knoll told attendees at the annual meeting of the American Academy of Psychiatry and the Law. “I want to invite you to look at this from the angle of those shootings that were able to be prevented or disrupted.” (Dr. Knoll said he used the term “disrupted” because it’s impossible to ever know for certain that a shooting was thwarted.)

It is difficult to track mass homicides that would have occurred but were disrupted, but one study Dr. Knoll cited combed through news reports and identified 57 interrupted mass homicides (Aggress Viol Behav. 2016 Sep-Oct;30:88-93). Most of those (77%) had been interrupted by family and friends or the general public reporting suspicious behavior.

It was while Dr. Knoll was leading the threat assessment subcommittee of the Syracuse School Safety Task Force that a potential school shooting threat arose.

A 22-year-old Chinese international student named Xiaofeng “Lincoln” Zhan walked into AJ’s Archery/The Gun Shop on March 12, asking to buy an AR-15. The AR-15 is the semiautomatic weapon of choice for most mass shooters.

Mr. Zhan should have been barred from purchasing a gun because he was an international student on a temporary visa. Under U.S. code, it is “unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person” is an alien who is “illegally or unlawfully in the United States” or “ has been admitted to the United States under a nonimmigrant visa.”

But the second provision was subject to certain exceptions, the first of which was that the person had been “admitted to the United States for lawful hunting or supporting purposes“ or was “in possession of a hunting license or permit lawfully issued in the United States.”

Mr. Zhan had a hunting license. He had taken a hunter safety course on March 11, the day before he entered the gun shop, and then bought a hunting license.

But the gun shop owner was not so easily persuaded. Mr. Zhan asked about “high-capacity shotguns” and said he belonged to a shooting club, yet he did not appear familiar with firearms. The gun shop owner was also skeptical because it didn’t make sense to use a high-capacity shotgun for hunting, and Mr. Zhan had just gotten his hunting license and didn’t know how to use the gun. Further, Mr. Zhan claimed that Syracuse University offered a class on how to use the gun – but the gun store owner knew that the university did not offer such a class.

The gun shop owner’s first thought was not that Mr. Zhan was a potential mass shooter but that he was a “secret shopper,” which Dr. Knoll defined as an undercover law enforcement officer who attempts to buy guns in a manner that should arouse suspicion in the store owner.

Ultimately, Zhan’s behavior was concerning and he made the owner feel uncomfortable. The owner captured Mr. Zhan’s information on U.S. ATF form 4473 and recorded his license plate. Then the gun shop owner contacted the Madison County Sheriff’s Office with the information.

The police opened an investigation that established that Mr. Zhan was a student enrolled at Syracuse University, which was on spring break at the time. The Syracuse Police Department arranged a joint meeting between the Onondaga County district attorney, Syracuse University Department of Public Safety, Onondaga County Sheriff’s Office, and the FBI to present their findings, including the fact that local high schools were planning walk-outs that might be potential targets.

Further investigation revealed that Mr. Zhan had been a student at Northeastern University in Boston in 2015, where he had asked a teacher how to get guns. The teacher emailed his supervisor, but the university police found no concerns.

Meanwhile, the police obtained a subpoena to get Mr. Zhan’s mental health records from Syracuse University. Mr. Zhan had sought psychiatric care at two facilities, Northeastern University in 2015 and Syracuse University in 2018. His mental health records revealed alcohol abuse, depression, suicidal thinking, anger problems, feelings of isolation and withdrawal, and his feeling that he might lose control or act violently, said Dr. Knoll, who is also professor of psychiatry at the university.

On March 13, the day after he had attempted to buy the gun, Syracuse University’s mental health services were contacted and briefed on Mr. Zhan. They filled out the paperwork for New York’s SAFE Act, which prevents people from buying a gun if a mental health professional makes the reasonable judgment that the individual might harm themselves or someone else.

The police investigation continued and found that Mr. Zhan had previously tried to buy an AR-15 at a Dick’s Sporting Goods store. He was denied because the SAFE Act prevents their sale.

Mr. Zhan, meanwhile, had gone to Mexico for the break and was due to return March 19. While he was away, an alarm allegedly went off in his apartment on March 16, leading the landlord to check on the apartment since he remembered previous police inquiries. He knocked on the door but there was no answer, so the landlord entered to do a safety check. He found ammunition and other concerning supplies.

The same day the landlord was checking Mr. Zhan’s apartment, students traveling with him in Mexico emailed Syracuse University about concerning behavior they observed in him. This behavior included signs of severe depression, verbalizing extremely negative thoughts, discussing suicide, drinking heavily, and making cuts to his forearms with the knife he possessed.

They also shared screenshots of messages they had seen him post in a social media group about feeling compelled to buy a gun and bulletproof vest and practice shooting.

Three days later, the police obtained a search warrant for Mr. Zhan’s apartment and vehicle. They found in his apartment high-powered optics, scopes, ammunition, targets from shooting ranges, receipts from shooting ranges, and similar equipment.

Ultimately, authorities revoked Mr. Zhan’s visa, enabling them to detain him at the airport when he returned from Mexico and deport him back to China.

After Mr. Zhan had returned to China, further investigation uncovered a series of texts between Mr. Zhan and his girlfriend in which he openly talks about wanting to shoot people.

“So, what went right here instead of what went wrong?” Dr. Knoll rhetorically asked. A lot of things: leakage of Mr. Zhan’s plans; fellow students seeing and reporting his electronic messages and concerning behaviors; the gun store owner’s skepticism and contact with the police; the landlord’s check on Mr. Zhan’s apartment; and the cooperation among local police, school authorities, and the school’s mental health services.

“There was also good communication among the threat assessment teams and law enforcement and the collaboration across disciplines,” Dr. Knoll said. Mass shootings have now “taken on more of a sociocultural phenomenon,” and “sociocultural problems require sociocultural solutions. I like these laws focusing on behaviors, not psychiatric diagnoses.”

He then reviewed potential interventions that might help identify or interfere with a planned incident or intent to commit one, including increased attention paid to suspicious behavior, third-party reporting of a potential shooter’s intent, and suicide prevention programs.

Dr. Knoll shared recent FBI research on 63 active shooters between 2000 and 2013 showing that the majority (77%) had been planning their attack for at least 1 week. Further, 46% have been preparing for 1 week before. The majority of those likely shooters also obtained their guns legally.

Although a quarter of those in the FBI study had some mental health diagnosis – predominantly depression or anxiety – the agency uncovered no significant correlation between mental illness and becoming a shooter.

The study concluded that,“absent specific evidence, careful consideration should be given to social and contextual factors that might interact with any mental health issue before concluding that an active shooting was ‘caused’ by a mental illness. In short, declarations that all active shooters must simply be mentally ill are misleading and unhelpful.”

Dr. Knoll reported no conflicts of interest.

AUSTIN, TEX. – While the media relentlessly reports on every mass shooting that occurs, the public hears less often about the shootings that never happened – because people were paying attention and taking action, according to James L. Knoll, IV, MD, director of forensic psychiatry at the State University of New York, Syracuse.

“We’ve learned a lot about risk factors [for mass shootings], we’ve learned a lot about associations and correlations, and it’s gotten us so far,” Dr. Knoll told attendees at the annual meeting of the American Academy of Psychiatry and the Law. “I want to invite you to look at this from the angle of those shootings that were able to be prevented or disrupted.” (Dr. Knoll said he used the term “disrupted” because it’s impossible to ever know for certain that a shooting was thwarted.)

It is difficult to track mass homicides that would have occurred but were disrupted, but one study Dr. Knoll cited combed through news reports and identified 57 interrupted mass homicides (Aggress Viol Behav. 2016 Sep-Oct;30:88-93). Most of those (77%) had been interrupted by family and friends or the general public reporting suspicious behavior.

It was while Dr. Knoll was leading the threat assessment subcommittee of the Syracuse School Safety Task Force that a potential school shooting threat arose.

A 22-year-old Chinese international student named Xiaofeng “Lincoln” Zhan walked into AJ’s Archery/The Gun Shop on March 12, asking to buy an AR-15. The AR-15 is the semiautomatic weapon of choice for most mass shooters.

Mr. Zhan should have been barred from purchasing a gun because he was an international student on a temporary visa. Under U.S. code, it is “unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person” is an alien who is “illegally or unlawfully in the United States” or “ has been admitted to the United States under a nonimmigrant visa.”

But the second provision was subject to certain exceptions, the first of which was that the person had been “admitted to the United States for lawful hunting or supporting purposes“ or was “in possession of a hunting license or permit lawfully issued in the United States.”

Mr. Zhan had a hunting license. He had taken a hunter safety course on March 11, the day before he entered the gun shop, and then bought a hunting license.

But the gun shop owner was not so easily persuaded. Mr. Zhan asked about “high-capacity shotguns” and said he belonged to a shooting club, yet he did not appear familiar with firearms. The gun shop owner was also skeptical because it didn’t make sense to use a high-capacity shotgun for hunting, and Mr. Zhan had just gotten his hunting license and didn’t know how to use the gun. Further, Mr. Zhan claimed that Syracuse University offered a class on how to use the gun – but the gun store owner knew that the university did not offer such a class.

The gun shop owner’s first thought was not that Mr. Zhan was a potential mass shooter but that he was a “secret shopper,” which Dr. Knoll defined as an undercover law enforcement officer who attempts to buy guns in a manner that should arouse suspicion in the store owner.

Ultimately, Zhan’s behavior was concerning and he made the owner feel uncomfortable. The owner captured Mr. Zhan’s information on U.S. ATF form 4473 and recorded his license plate. Then the gun shop owner contacted the Madison County Sheriff’s Office with the information.

The police opened an investigation that established that Mr. Zhan was a student enrolled at Syracuse University, which was on spring break at the time. The Syracuse Police Department arranged a joint meeting between the Onondaga County district attorney, Syracuse University Department of Public Safety, Onondaga County Sheriff’s Office, and the FBI to present their findings, including the fact that local high schools were planning walk-outs that might be potential targets.

Further investigation revealed that Mr. Zhan had been a student at Northeastern University in Boston in 2015, where he had asked a teacher how to get guns. The teacher emailed his supervisor, but the university police found no concerns.

Meanwhile, the police obtained a subpoena to get Mr. Zhan’s mental health records from Syracuse University. Mr. Zhan had sought psychiatric care at two facilities, Northeastern University in 2015 and Syracuse University in 2018. His mental health records revealed alcohol abuse, depression, suicidal thinking, anger problems, feelings of isolation and withdrawal, and his feeling that he might lose control or act violently, said Dr. Knoll, who is also professor of psychiatry at the university.

On March 13, the day after he had attempted to buy the gun, Syracuse University’s mental health services were contacted and briefed on Mr. Zhan. They filled out the paperwork for New York’s SAFE Act, which prevents people from buying a gun if a mental health professional makes the reasonable judgment that the individual might harm themselves or someone else.

The police investigation continued and found that Mr. Zhan had previously tried to buy an AR-15 at a Dick’s Sporting Goods store. He was denied because the SAFE Act prevents their sale.

Mr. Zhan, meanwhile, had gone to Mexico for the break and was due to return March 19. While he was away, an alarm allegedly went off in his apartment on March 16, leading the landlord to check on the apartment since he remembered previous police inquiries. He knocked on the door but there was no answer, so the landlord entered to do a safety check. He found ammunition and other concerning supplies.

The same day the landlord was checking Mr. Zhan’s apartment, students traveling with him in Mexico emailed Syracuse University about concerning behavior they observed in him. This behavior included signs of severe depression, verbalizing extremely negative thoughts, discussing suicide, drinking heavily, and making cuts to his forearms with the knife he possessed.

They also shared screenshots of messages they had seen him post in a social media group about feeling compelled to buy a gun and bulletproof vest and practice shooting.

Three days later, the police obtained a search warrant for Mr. Zhan’s apartment and vehicle. They found in his apartment high-powered optics, scopes, ammunition, targets from shooting ranges, receipts from shooting ranges, and similar equipment.

Ultimately, authorities revoked Mr. Zhan’s visa, enabling them to detain him at the airport when he returned from Mexico and deport him back to China.

After Mr. Zhan had returned to China, further investigation uncovered a series of texts between Mr. Zhan and his girlfriend in which he openly talks about wanting to shoot people.

“So, what went right here instead of what went wrong?” Dr. Knoll rhetorically asked. A lot of things: leakage of Mr. Zhan’s plans; fellow students seeing and reporting his electronic messages and concerning behaviors; the gun store owner’s skepticism and contact with the police; the landlord’s check on Mr. Zhan’s apartment; and the cooperation among local police, school authorities, and the school’s mental health services.

“There was also good communication among the threat assessment teams and law enforcement and the collaboration across disciplines,” Dr. Knoll said. Mass shootings have now “taken on more of a sociocultural phenomenon,” and “sociocultural problems require sociocultural solutions. I like these laws focusing on behaviors, not psychiatric diagnoses.”

He then reviewed potential interventions that might help identify or interfere with a planned incident or intent to commit one, including increased attention paid to suspicious behavior, third-party reporting of a potential shooter’s intent, and suicide prevention programs.

Dr. Knoll shared recent FBI research on 63 active shooters between 2000 and 2013 showing that the majority (77%) had been planning their attack for at least 1 week. Further, 46% have been preparing for 1 week before. The majority of those likely shooters also obtained their guns legally.

Although a quarter of those in the FBI study had some mental health diagnosis – predominantly depression or anxiety – the agency uncovered no significant correlation between mental illness and becoming a shooter.

The study concluded that,“absent specific evidence, careful consideration should be given to social and contextual factors that might interact with any mental health issue before concluding that an active shooting was ‘caused’ by a mental illness. In short, declarations that all active shooters must simply be mentally ill are misleading and unhelpful.”

Dr. Knoll reported no conflicts of interest.

AUSTIN, TEX. – While the media relentlessly reports on every mass shooting that occurs, the public hears less often about the shootings that never happened – because people were paying attention and taking action, according to James L. Knoll, IV, MD, director of forensic psychiatry at the State University of New York, Syracuse.

“We’ve learned a lot about risk factors [for mass shootings], we’ve learned a lot about associations and correlations, and it’s gotten us so far,” Dr. Knoll told attendees at the annual meeting of the American Academy of Psychiatry and the Law. “I want to invite you to look at this from the angle of those shootings that were able to be prevented or disrupted.” (Dr. Knoll said he used the term “disrupted” because it’s impossible to ever know for certain that a shooting was thwarted.)

It is difficult to track mass homicides that would have occurred but were disrupted, but one study Dr. Knoll cited combed through news reports and identified 57 interrupted mass homicides (Aggress Viol Behav. 2016 Sep-Oct;30:88-93). Most of those (77%) had been interrupted by family and friends or the general public reporting suspicious behavior.

It was while Dr. Knoll was leading the threat assessment subcommittee of the Syracuse School Safety Task Force that a potential school shooting threat arose.

A 22-year-old Chinese international student named Xiaofeng “Lincoln” Zhan walked into AJ’s Archery/The Gun Shop on March 12, asking to buy an AR-15. The AR-15 is the semiautomatic weapon of choice for most mass shooters.

Mr. Zhan should have been barred from purchasing a gun because he was an international student on a temporary visa. Under U.S. code, it is “unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person” is an alien who is “illegally or unlawfully in the United States” or “ has been admitted to the United States under a nonimmigrant visa.”

But the second provision was subject to certain exceptions, the first of which was that the person had been “admitted to the United States for lawful hunting or supporting purposes“ or was “in possession of a hunting license or permit lawfully issued in the United States.”

Mr. Zhan had a hunting license. He had taken a hunter safety course on March 11, the day before he entered the gun shop, and then bought a hunting license.

But the gun shop owner was not so easily persuaded. Mr. Zhan asked about “high-capacity shotguns” and said he belonged to a shooting club, yet he did not appear familiar with firearms. The gun shop owner was also skeptical because it didn’t make sense to use a high-capacity shotgun for hunting, and Mr. Zhan had just gotten his hunting license and didn’t know how to use the gun. Further, Mr. Zhan claimed that Syracuse University offered a class on how to use the gun – but the gun store owner knew that the university did not offer such a class.

The gun shop owner’s first thought was not that Mr. Zhan was a potential mass shooter but that he was a “secret shopper,” which Dr. Knoll defined as an undercover law enforcement officer who attempts to buy guns in a manner that should arouse suspicion in the store owner.

Ultimately, Zhan’s behavior was concerning and he made the owner feel uncomfortable. The owner captured Mr. Zhan’s information on U.S. ATF form 4473 and recorded his license plate. Then the gun shop owner contacted the Madison County Sheriff’s Office with the information.

The police opened an investigation that established that Mr. Zhan was a student enrolled at Syracuse University, which was on spring break at the time. The Syracuse Police Department arranged a joint meeting between the Onondaga County district attorney, Syracuse University Department of Public Safety, Onondaga County Sheriff’s Office, and the FBI to present their findings, including the fact that local high schools were planning walk-outs that might be potential targets.

Further investigation revealed that Mr. Zhan had been a student at Northeastern University in Boston in 2015, where he had asked a teacher how to get guns. The teacher emailed his supervisor, but the university police found no concerns.

Meanwhile, the police obtained a subpoena to get Mr. Zhan’s mental health records from Syracuse University. Mr. Zhan had sought psychiatric care at two facilities, Northeastern University in 2015 and Syracuse University in 2018. His mental health records revealed alcohol abuse, depression, suicidal thinking, anger problems, feelings of isolation and withdrawal, and his feeling that he might lose control or act violently, said Dr. Knoll, who is also professor of psychiatry at the university.

On March 13, the day after he had attempted to buy the gun, Syracuse University’s mental health services were contacted and briefed on Mr. Zhan. They filled out the paperwork for New York’s SAFE Act, which prevents people from buying a gun if a mental health professional makes the reasonable judgment that the individual might harm themselves or someone else.

The police investigation continued and found that Mr. Zhan had previously tried to buy an AR-15 at a Dick’s Sporting Goods store. He was denied because the SAFE Act prevents their sale.

Mr. Zhan, meanwhile, had gone to Mexico for the break and was due to return March 19. While he was away, an alarm allegedly went off in his apartment on March 16, leading the landlord to check on the apartment since he remembered previous police inquiries. He knocked on the door but there was no answer, so the landlord entered to do a safety check. He found ammunition and other concerning supplies.

The same day the landlord was checking Mr. Zhan’s apartment, students traveling with him in Mexico emailed Syracuse University about concerning behavior they observed in him. This behavior included signs of severe depression, verbalizing extremely negative thoughts, discussing suicide, drinking heavily, and making cuts to his forearms with the knife he possessed.

They also shared screenshots of messages they had seen him post in a social media group about feeling compelled to buy a gun and bulletproof vest and practice shooting.

Three days later, the police obtained a search warrant for Mr. Zhan’s apartment and vehicle. They found in his apartment high-powered optics, scopes, ammunition, targets from shooting ranges, receipts from shooting ranges, and similar equipment.

Ultimately, authorities revoked Mr. Zhan’s visa, enabling them to detain him at the airport when he returned from Mexico and deport him back to China.

After Mr. Zhan had returned to China, further investigation uncovered a series of texts between Mr. Zhan and his girlfriend in which he openly talks about wanting to shoot people.

“So, what went right here instead of what went wrong?” Dr. Knoll rhetorically asked. A lot of things: leakage of Mr. Zhan’s plans; fellow students seeing and reporting his electronic messages and concerning behaviors; the gun store owner’s skepticism and contact with the police; the landlord’s check on Mr. Zhan’s apartment; and the cooperation among local police, school authorities, and the school’s mental health services.

“There was also good communication among the threat assessment teams and law enforcement and the collaboration across disciplines,” Dr. Knoll said. Mass shootings have now “taken on more of a sociocultural phenomenon,” and “sociocultural problems require sociocultural solutions. I like these laws focusing on behaviors, not psychiatric diagnoses.”

He then reviewed potential interventions that might help identify or interfere with a planned incident or intent to commit one, including increased attention paid to suspicious behavior, third-party reporting of a potential shooter’s intent, and suicide prevention programs.

Dr. Knoll shared recent FBI research on 63 active shooters between 2000 and 2013 showing that the majority (77%) had been planning their attack for at least 1 week. Further, 46% have been preparing for 1 week before. The majority of those likely shooters also obtained their guns legally.

Although a quarter of those in the FBI study had some mental health diagnosis – predominantly depression or anxiety – the agency uncovered no significant correlation between mental illness and becoming a shooter.

The study concluded that,“absent specific evidence, careful consideration should be given to social and contextual factors that might interact with any mental health issue before concluding that an active shooting was ‘caused’ by a mental illness. In short, declarations that all active shooters must simply be mentally ill are misleading and unhelpful.”

Dr. Knoll reported no conflicts of interest.