The gunman, who shot dead four people in a New York apartment, was targeting the National Football League office but took the wrong elevator.

New York City Mayor Eric Adams told WPIX-TV, as OPB, "He seemed to have blamed the NFL."

"The NFL headquarters was located in the building, and he mistakenly went up the wrong elevator bank," the Mayor said.

At least four people, including a police officer, were killed after a gunman opened fire after entering a Midtown skyscraper in New York on Monday.

The shooter was identified as 27-year-old Shane Tamura.

According to reports, Tamura died due to a self-inflicted injury.

The 44-year-old attacker barged into the 44-storey building, which also houses major corporate offices like  Blackstone and the NFL.

Armed with a rifle, the attacker opened fire at around 6:30 p.m. during the evening rush, cops and law enforcement sources told The New York Post.

Tamura, who authorities said had a “mental health history,” unleashed his rampage after setting foot in the lobby, first gunning down officer Didarul Islam, NYPD Commissioner Jessica Tisch said at a Monday evening press conference as quoted by the newspaper.