Manhattan shooting suspect claimed to have CTE, mentioned NFL in note, sources say

The tragic mass shooting that occurred in a Midtown Manhattan office building on Monday has left the nation in shock. The 27-year-old suspect, Shane Tamura, allegedly killed four people and wounded a fifth before taking his own life. Police sources revealed that Tamura carried a note in his pocket claiming he suffered from CTE (chronic traumatic encephalopathy) and requested that his brain be studied. This note also made references to the NFL, with Mayor Eric Adams stating that Tamura appeared to blame the NFL for his injury.

CTE is a brain disease associated with repeated head trauma, commonly found in athletes such as football players, hockey players, and boxers. It can only be definitively diagnosed through an autopsy, where specialists look for specific changes in the brain, including tau protein abnormalities. Symptoms of CTE typically manifest years after the initial head trauma and may include memory loss, mood changes, confusion, and cognitive impairment.

Tamura, who had a documented mental health history, had previously undergone two Mental Health Crisis Holds in Nevada, the most recent one in 2024. These holds allow individuals to be detained for up to 72 hours if they are deemed a threat to themselves or others. Additionally, Tamura obtained a concealed carry license in 2022 and had a prior arrest for trespassing in the state.

The shooting took place at 345 Park Ave., where the NFL’s headquarters are located. Tamura mistakenly entered Rudin Management on the building’s 33rd floor, where he carried out additional shootings. The fifth victim, who was critically injured in the attack, underwent surgery and is now in stable condition.

As the investigation into this tragic event continues, it serves as a stark reminder of the devastating consequences of untreated mental health issues and the long-term impact of head injuries. Our thoughts are with the victims and their families during this difficult time.

Please stay tuned for further updates on this developing story. Contributions to this report were made by ABC News’ Darren Reynolds and Liz Neporent.