The Buffalo shooting suspect showed signs of violent behavior and was left untreated. Violence prevention experts say troubled youth like him need long-term support

Investigators stand outside the Tops Friendly Market on Saturday, May 21, 2022, in Buffalo, New York.

(CNN)The 18-year-old White man who opened fire at a Buffalo supermarket, killing 10 and injuring three, was first known to authorities in 2021 after making a generalized threat while attending his high school, according to Buffalo Police Commissioner Joseph Gramaglia.

New York State Police took the suspect to a hospital for a psychiatric evaluation after he made a threat and worked on a school project that mentioned murder-suicides. But authorities released him after a day-and-a-half after determining that his threat was not specific enough to warrant further action, investigators have previously said. This allowed him to legally purchase the AR-15-style weapon he used in the attack.
The case of the Buffalo suspect -- who pleaded not guilty to the 25-count indictment against him -- exemplifies how high-risk adolescents, left untreated and unmonitored, can fall through the cracks of the system that aims to disrupt potentially violent behaviors, which allows those young people to carry out deadly acts of violence, several experts tell CNN.
Experts researching and developing approaches for long-term treatment to troubled teenagers say that they demand intensive services over a long period of time across agencies in mental health, community and law enforcement.
High-risk adolescents are characterized by antisocial disorders, social withdrawal, depressed mood and a lack of empathy or remorse, according to a National Policing Institute report released earlier this year on managing high-risk adolescents in community contexts. Those who become radicalized by extremist groups or harbor dangerous, racist views, experts say, require a more complex treatment plan that seeks to address the underlying causes of their ideology and reframe their mindset entirely.
The role of police in dealing with high-risk adolescents is to respond to an articulated or imminent threat of danger, an arrest, or transportation to a psychiatric or crisis center for an evaluation, according to Frank Straub, director of the National Policing Institute's (NPI) Center for Targeted Violence Prevention.
From there, experts say the individualized treatment plan determines whether the person should return to school or be homeschooled, undergo therapy or be taken to a psychiatric facility and be involved in pro-social groups such as sports or after school activities.
But experts assert that there isn't a consistent or widespread system in place that provides treatment for people like the alleged Buffalo shooter that connects them with long-term guidance, regular interaction and mentoring that has been proven in studies to be effective in rehabilitation.
Part of the problem, experts say, is that many communities don't have the experience or funding to effectively treat people who articulate a threat to themselves or others.
"One of the things that we see as a shortfall is that assessment is a continuous process. You don't do one threat assessment and say if an individual is at risk or not and then release him," Straub said.
Behavioral threat assessment teams in schools are typically composed of law enforcement officers, school psychologists or social workers, school administrators and, in some cases, teachers. Threat assessment teams -- which also operate in university and private sector settings -- are designed to identify and manage potentially dangerous people in an effort to thwart violence.
But it is equally important, experts say, to deploy trained professionals who connect teenagers and their families to long-term counsel, regular check-ins, psychological treatment and community-based programs.
The research into this multidisciplinary approach is targeting what Straub calls the "gray area" in which at-risk adolescents fall between mental health, law enforcement and criminal justice system responses.

Case study highlights gap in mental health system

Straub leads the Averted School Violence (ASV) project, a national database developed by NPI that analyzes averted and completed school attacks.
A recent NPI report includes the 2018 case of a Michigan high school student who displayed mental illness and suicidal ideation, the report says. He also had chronic social and academic difficulties and showed signs of psychopathic tendencies.
In February 2018, the school's principal observed the context of one of his notebooks "filled with detailed notes regarding his experimentation with homemade explosives" and called in a police officer, who then requested an evaluator to conduct a threat assessment.
Although there was a concern, the assessment found that his behavior "did not meet the criteria for arrest, school disciplinary action, or referral to a mental health provider," the report said. Law enforcement officers also searched the teenager's room but found no concerning materials, which closed the case.
In March, however, the teenager's mother found two sawed-off shotguns in the drawer of his room and brought him into police custody, where she reported that he was plotting to attack his high school in Paw Paw using modified firearms and homemade explosives.
The teenager was arrested and remanded to juvenile detention and was later sentenced to spend a year in a residential treatment center, where he remained until his 19th birthday. In July 2021, he was released from all legal supervision by a judge.
One month after his release, he went to a beach pier in South Haven, Michigan, armed with two guns. On August 20, 2021, he shot two people, killing one of them on a pier. The teenager made his way toward the beach, firing several shots at people, missing them as they ran for cover, before fatally shooting himself.
The report's authors concluded that the case of the South Haven shooter proves the need for specially trained community-based teams that can provide long-term counsel and mentoring to at-risk adolescents and their families.
The Buffalo supermarket shooting suspect arrives for a hearing at the Erie County Courthouse on May 19, 2022, in Buffalo, New York.
"Had such a team existed, it could have been engaged immediately following the discovery of his notebook by his teacher, the risk evaluation, and law enforcement response. A second opportunity to engage such a team presented itself upon his release from the juvenile facility," the report stated.
There are parallels, according to Straub, between the South Haven shooter and the alleged Buffalo shooter -- both cases illustrate how the country's mental health system doesn't have the capacity to allocate intensive resources and ongoing evaluation to them.
In the case of the Buffalo suspect, Staub said, "we see there's a psychiatric evaluation, but after a couple of days he's back out in the community. There's no team, no entity to hand that person off to so they can be mentored and evaluated regularly."
In the case of the South Haven shooter, Straub added, "there's a clear articulation by at least one psychiatrist in the juvenile facility that he was still high-risk and in need of continuing support in a community context. But that doesn't happen."

The period after an articulated threat is 'particularly high-risk'

Elizabeth Jeglic, a psychology professor at John Jay College, says research suggests that the period after a threat is made is "particularly h