When 27-year-old Shane Devon Tamura entered a Midtown Manhattan office tower armed with an M4-style assault rifle and opened fire—killing four people, including a heroic off-duty NYPD officer, before taking his own life—it marked yet another entry in the grim ledger of American mass violence.
Tamura left no manifesto, no political motive, no connection to the victims…only a note referencing brain trauma and a request that his brain be studied for signs of chronic traumatic encephalopathy (CTE)—an apparent effort to explain a faltering mind. His fixation on head trauma and failed football dreams was likely part of the delusion that drove him across the country to 435 Park Ave, where the NFL headquarters is located.
Unless further evidence should emerge to suggest otherwise, it seems clear that Tamura’s act wasn’t fueled by ideological zealotry or social alienation. Rather, it was driven by untreated mental illness. In this context, his murderous rampage follows a pattern we’ve witnessed far too often: a young man in mental decline, ignored, derided, and unaided until tragedy strikes. Aurora, Tucson, Newtown, Charleston, Virginia Tech—and now, Midtown Manhattan. In this now too familiar scenario, we cycle through shock, outrage, and hollow political gestures—only to lapse into denial and inaction. The headlines fade; our attention shifts; the next tragedy brews.
As a psychiatrist with four decades of clinical experience, research expertise around the causes of mass violence, and direct involvement in high-profile cases—including James Holmes (Aurora) and Jared Loughner (Tucson)—I can confidently say that these tragedies are preventable. But only if we stop treating inaction as neutrality.
Yes, access to high-powered firearms magnifies the carnage. Yes, tighter gun control laws would curtail the ability of perpetrators like Tamura to carry out their acts of mass violence. But we would be remiss not to acknowledge that the fundamental factor in cases like Tamura’s is not ideology or weaponry—it’s untreated mental illness.
Consider Travis Reinhardt, who, after years of displaying erratic and deranged public behavior, committed a mass shooting at a Tennessee Waffle House. Or Arthur DaRosa, discharged from a hospital after reporting delusions, who killed two people the next day. Or Yoselyn Ortega, a nanny in clear psychiatric crisis, dismissed with a $200 bill and a diagnosis of anxiety—only to later murder the two children in her care. In each case—including Tamura’s—someone noticed a person in distress. A doctor. A relative. A friend. A bystander. But no one felt empowered, or was willing, to act.
We’re not failing because we lack understanding. We’re failing because we refuse to respond as a society and as individuals.
Personal mass murder involves a single individual and “personal” motivation, such as acute emotional events, a desire for revenge, infamy, extreme bias or political ideology, or symptoms of mental illness. Though mass violence accounts for less than 0.1% of all violent deaths in the U.S. each year, it produces an outsized effect on the population due to the dissemination of these events by the media. When these tragedies occur, they resonate in the echo chamber of broadcast, print, and online media. The circulate through news outlets, becoming irresistible clickbait and triggering a cascade of fear throughout the populace.
The repetitive occurrence of these crimes in recent decades exerts insidious effects on the national psyche – e.g., a sense of foreboding and helplessness in public places. Rather than seeking to understand and resolve the root causes of mass personal violence, however, we continue to pile on layers of security, effectively turning our society into a prison state.
We’re not failing because we lack understanding. We’re failing because we refuse to respond as a society and as individuals.
So if we were determined that this kind of preventable tragedy should not happen again, what would we need to do?
First, we must emphasize early identification. Most serious mental illnesses begin in adolescence or young adulthood, yet our system waits until people are actively suicidal, violent, or incarcerated before intervening.
That’s like treating cancer only after it has metastasized.
We need to be proactive because the public lacks awareness of mental illness, and those suffering are reluctant to seek help when they are in mental distress. Therefore, we must embed mental health professionals in primary care clinics, educational institutions, and workplaces. Teachers, counselors, and primary care providers should be trained to recognize early symptoms of mental illness, and they must have reliable and accessible referral networks with adequate capacity. They must also be trained in risk assessment.
These are not radical ideas. They are basic public health strategies.
Second, we need a comprehensive, continuous care infrastructure – hospital beds, ambulatory clinics, residential facilities, and a trained multi-disciplinary work force. Mental illness cannot be managed by a doctor with a single prescription.
Third, and most urgently, we must overcome our reluctance to mandate treatment for individuals who are too sick to seek help on their own. Our country’s ethos of self-determination and personal autonomy does not serve the best interests of the mentally ill when it allows them to suffer, languish, and all too often “die with their rights on.” We have effective treatments that these people will benefit from even if they say they believe they don’t need or want them.
Allowing someone to descend into psychosis and become vulnerable and violent while “respecting their autonomy” is not compassion. It’s abandonment.
We don’t hesitate to isolate and treat individuals with active tuberculosis, meningitis, or sexually transmitted diseases in the interest of protecting public safety. Why should untreated psychosis be different? This is why Assisted Outpatient Treatment (AOT) laws exist in 45 states, allowing courts to require care for individuals deemed a clear risk to themselves or others. The data is clear: AOT reduces hospitalizations, arrests, homelessness, and violent incidents. Yet these laws remain drastically underused, largely due to the fear that compelling treatment violates civil liberties.
Mass violence is a solvable problem, but it requires structural and policy reform – a continuum of care, a trained workforce, and legislation permitting proactive treatment based on the principle of parens patriae, which empowers the government to intervene when its citizens are unable to care for themselves.
Allowing someone to descend into psychosis and become vulnerable and violent while “respecting their autonomy” is not compassion. It’s abandonment.
Most importantly, it requires political will, sustained investment, and a willingness to confront uncomfortable truths. The goal is not to criminalize mental illness. It’s to break the chain of events that leads from unrecognized symptoms to irreversible tragedy. Albert Einstein is credited with saying that insanity is doing the same thing over and over and expecting different results. By that measure, America’s response to mass violence is its own kind of madness.
Shane Tamura didn’t have to die. Nor did the officer who tried to stop him. Nor the many others whose deaths were not senseless, but foreseeable.
We act like we’re powerless.
We’re not.
We’re just pretending to be.
Editor’s note (Sept. 26, 2025): Since this essay was published, the NYC medical examiner confirmed that Tamura’s brain displayed signs of low-stage CTE. This finding adds a neurological dimension to the case but reinforces the argument that systemic failures in early brain and mental health detection remain our greatest vulnerability.
The Tumbler Ridge mass shooting in Canada likely underscores another profound failure in our mental health care system. Despite the promise of universal coverage, too many people still do not receive the treatment they need. I have experienced this system from both sides—working within it and relying on it as a patient. Living with schizoaffective disorder, I have been hospitalized involuntarily and, in retrospect, I am grateful for that intervention. Without it, my condition would have continued to deteriorate. I share the view that the balance between personal autonomy and beneficence has shifted too far toward individual rights, often at the expense of timely and effective care.