The gunman responsible for the July Midtown Manhattan shooting that killed four people, Shane Tamura, was diagnosed with low-stage CTE. Officials confirmed the findings after analyzing his brain tissue. Tamura, a former football player, left notes referencing CTE and his belief that the NFL concealed brain injury dangers. Experts state low-stage CTE can significantly impact judgment and behavior, underscoring the need to prevent brain trauma in young athletes.

Prepared by Emily Rhodes and reviewed by editorial team.