Experts say no 'instant answer' as to whether gunman had CTE - ESPN

Brain experts say it could take weeks to learn whether Shane Tamura, the 27-year-old gunman who killed four people at a Manhattan office building before killing himself Monday, had chronic traumatic encephalopathy, a degenerative brain disease that can be diagnosed only after someone has died.

The process of testing for CTE, according to brain researchers and experts who spoke with ESPN, involves preserving, dissecting, staining and examining tissue samples from different regions of the brain under a microscope.

«That process can be a week, two [weeks],» said Dr. Brent Masel, a neurologist on the board of the Brain Injury Association of America. "… So there will not be an instant answer to that."

Investigators believe Tamura, a Las Vegas casino worker, was trying to get to the NFL offices after shooting several people Monday in the building's lobby but entered the wrong set of elevator banks.

Tamura, who played high school football in California roughly a decade ago but never in the NFL, had a history of mental illness, police said.

A note found in Tamura's wallet suggested he suffered from CTE and held a grievance against the NFL. In the note, he repeatedly said he was sorry and asked that his brain be studied for CTE, according to police.

Asked whether Tamura would be tested for CTE, New York City Mayor Eric Adams told CNN that the city's medical examiner would make that determination. The City of New York Office of Chief Medical Examiner told ESPN in an email Tuesday that an «examination of brain (neuropathology) is part of the complete autopsy process.»

«Additional testing for the complete autopsy record… will be ongoing,» but the City of New York Office of Chief Medical Examiner did not respond when asked about the