After killing four and taking his own life, Shane Tamura — a former football player at two L.A.-area high schools — left behind a suicide note, authorities say, alleging he had the brain disease CTE.

He did have a note on him. The note alluded to that he felt he had CTE, a known brain injury for those who participate in contact sports. He appeared to have blamed the NFL for

Shane Tamura, a former football player at Golden Valley and Granada Hills high schools, entered a New York skyscraper and began spraying bullets, police say.