Quick Summary In July 2025, a tragic shooting occurred at an office building in Midtown Manhattan, where four people were killed and others were injured. The shooter reportedly mentioned chronic traumatic encephalopathy (CTE), a brain disease linked to repeated head trauma, as a factor in his mental health and violent actions. This has brought renewed public attention to CTE, a progressive neurodegenerative condition with serious symptoms and complex effects. The Manhattan Shooting and the CTE Connection On July 28, 2025, Shane Tamura, a 27-year-old man from Las Vegas, opened fire inside the 345 Park Avenue office building, killing four people, including an off-duty NYPD officer and Blackstone executive Wesley LePatner, before dying by suicide. Investigations revealed that Tamura had a history of mental health issues. A note found after the shooting referenced his struggles with brain trauma and specifically mentioned concerns about CTE, a disease increasingly discussed with contact sports and repeated head injuries. This connection between the shooting and CTE has spurred questions about what CTE is, how it develops, and whether it could contribute to behavioral changes or violent acts. What Is CTE (Chronic Traumatic Encephalopathy)? CTE is a progressive brain condition caused by repeated blows or impacts to the head. Originally identified in boxers as “punch drunk syndrome,” the disease has now been found in athletes playing football, hockey, and rugby and in military veterans exposed to blasts. Key characteristics of CTE include: Cause: Multiple concussions and sub-concussive impacts over time.Pathology: Abnormal accumulation of tau protein in brain tissue, detectable only after death through autopsy.Symptoms: Mood disorders, memory loss, aggression, impaired judgment, and cognitive decline. CTE is difficult to diagnose in living individuals, relying instead on clinical history and symptom patterns. Symptoms and Progression Symptoms usually appear years or decades after the initial brain trauma and can include: Early changes: Depression, irritability, impulsivity, anxiety, and poor concentration.Progressive decline: Memory loss, confusion, aggression, and dementia-like symptoms.Severe stages: Problems with movement, speech, and swallowing may occur. Not everyone with repeated head trauma develops CTE, but the risk increases with exposure. CTE and Violence: What Do We Know? While CTE has been linked to mood dysregulation, impulsivity, and sometimes aggressive behavior, it is important to state that: Not all people with CTE are violent.Violence is influenced by multiple factors, including mental health, environment, and genetics.CTE cannot be definitively diagnosed in someone while alive; speculation about the shooter’s condition remains preliminary. In the Manhattan shooting case, Tamura’s note referencing CTE has reignited public debate on the long-term effects of brain injuries and mental health care for vulnerable individuals. Research and Prevention CTE research is ongoing, with efforts focused on: Developing non-invasive diagnostic tools (imaging, biomarkers).Understanding why some individuals develop CTE and others don’t.Improving protective measures in sports and other high-risk activities.Providing support and treatment for mood and behavioral symptoms. Why Does This Matter Now? The Manhattan shooting tragedy highlights the urgent need to understand brain injuries and their possible behavioral consequences. It also underscores the importance of mental health support and early intervention for people at risk.