A gunman armed with an assault-style rifle killed four people inside a Manhattan skyscraper that houses the headquarters of the NFL and offices of several major financial firms, New York City officials have said.

One of the four victims killed in the gun violence was a 36-year-old New York Police Department officer who immigrated to the US from Bangladesh. Mayor Eric Adams described the officer, who had been on the force for more than three years, as a “true blue” hero.

Authorities offered few details about the three other victims killed by the suspect – two men and a woman. A third male was seriously injured by the gunfire and was “fighting for his life” in a nearby hospital, the mayor said.

Police officer killed in shooting was ‘protecting New Yorkers’

New York Police Commissioner Jessica Tisch said the gunman, identified as Shane Tamura, 27-year-old Las Vegas resident with a history of mental illness, had driven cross-country to New York in recent days.

The gunman was believed to have acted alone, and investigators had yet to determine a possible motive for the shooting, Ms Tisch told reporters at a late-night news briefing.

A group of people carrying a stretcher
New York Police Commissioner Jessica Tisch said the gunman resided in Las Vegas

“Pure evil came to the heart of our city and struck innocent people and one of our police officers who were protecting those people,” Patrick Hendry, president of the Police Benevolent Association, said at the press conference.

The murdered policeman, Didarul Islam, a father of two whose wife is pregnant with a third child, was working at the time as part of an NYPD programme that allows its uniformed patrol officers to be assigned as security detail in commercial establishments.

The shooting began in the reception of the Park Avenue tower in Midtown Manhattan, then shifted to the upper-story offices of a management company as the suspect took the elevator to the 33rd floor. It ended when the gunman took his own life, Ms Tisch told reporters.

A photo of the suspect that CNN said was shared by police showing a gunman walking into the building carrying a rifle was published by a number of major news media outlets. Preliminary checks of the suspect’s background did not show a significant criminal history, the report added, citing officials.

The skyscraper at 345 Park Avenue houses offices of a number of financial institutions, including Blackstone and KPMG, along with the headquarters of the National Football League.

A large police presence converged on the area around the tower.

“I just saw a lot of commotion and cops and people screaming,” said Russ McGee, who was using the gym adjacent to the skyscraper, told Reuters in an interview near the scene.

The FBI said agents from its New York field office were also responding to provide support at the scene.