Police said Tamura had a history of mental illness, and a rambling note found on his body suggested he had a grievance against the NFL over an unsubstantiated claim that he suffered from chronic

A gunman who killed four people inside a Manhattan office tower blamed his mental health problems on the National Football League and intended to target the league’s headquarters upstairs but took the wrong elevator,

Officials say the suspect, identified as 27-year-old Shane Tamura, acted alone and died from an "apparent self-inflicted gunshot wound".