A gunman who opened fire in the centre of New York City and killed four people allegedly left a note that appeared to blame the National Football League (NFL) for a brain injury.
The shooter, 27-year-old Shane Tamura from Las Vegas, took his own life after shooting inside a glitzy Manhattan skyscraper that is home to the Irish consulate and firms including Blackstone and the NFL.
The city's Mayor, Eric Adams, said the assailant was carrying a note saying that he believed he had CTE, a form of brain injury triggered by blows to the head.
He also said Tamura played football when he was a teenager but didn't play for the NFL.
"[Tamura] did have a note on him", Adams told CBS News.
"The note alluded to that he felt he had CTE, a known brain injury for those who participate in contact sports."
Legions of emergency vehicles rushed to the skyscraper at 345 Park Avenue following the shooting.
A police officer, named locally as Didarul Islam, was among the victims.
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| NYPDIslam was working private security at the time and was said to have been shot in the back.
In tribute to the officer, New York City Police Department (NYPD) said: "He was protecting New Yorkers from danger when his life was tragically cut short today.
"We join in prayer during this time of incomprehensible pain. We will forever honour his legacy."
Tamura died of a self-inflicted gunshot wound, senior New York City officials said.
Emergency services pictured at the scene of the shooting
|REUTERS
Preliminary checks did not show a "significant criminal background", officials told CNN.
The FBI joined police and other emergency services at the scene of the shooting.
Adams meanwhile ordered locals to not go outside in the local area.
"New Yorkers: there is an active shooter investigation taking place in Midtown right now, the New York City Mayor said.
"Please take proper safety precautions if you are in vicinity and do not go outside if you are near Park Avenue and East 51st Street."