Inside New York shooter's suicide note that claims he had brain damage owing to American football

Shane Tamura, who shot and killed four people at an office tower in Manhattan, left a ‘suicide note’ claiming the National Football League (NFL) was responsible for chronic traumatic encephalopathy (CTE), a brain condition he said he was suffering from. Meanwhile, the police are still investigating the motive behind the attack, which is now considered the worst mass shooting in a quarter of a century

Explainers