NYC gunman 'took wrong lift' during NFL HQ attack as eyewitnesses reveal terrifying details of fatal shooting

The former footballer suspected of shooting dead four people in New York City entered a different floor than intended before opening fire, it has been claimed.

Shane Devon Tamura, 27, entered a skyscraper building on 345 Park Avenue, New York City, on Monday night, according to local authorities.

Surveillance footage from outside the building has shown Tamura parking a BMW before making his entrance.

It is said that he then opened fire, using an M4 rifle, in both the lobby and 33rd floor of the building, before then killing himself.

A total of five people, including the gunman and an NYPD officer, were killed in the attack. An NFL employee has also been seriously injured, according to NFL commissioner Roger Goodall.

Police are yet to determine a definitive motive for the attack, which took place at around 6:00PM ET.

According to CNN, Tamura left a note at the scene in which he claimed that he was suffering from chronic traumatic encephalopathy (CTE), a neurodegenerative brain disease caused by repeated blows to the head.

He also wrote: "Please study my brain."

An eye-witness told AFP that the 27-year-old 'went floor-by-floor' upon entering the building, with another stating: "He walked right into a building right next door. We saw the photo of him walking through the same area that I walked through to get lunch here. You would think it won't happen to you, then it does."

New York City Mayor Eric Adams has since held a press conference in the aftermath of the attack.

NYC gunman 'entered wrong set of lifts'

According to Adams, authorities believe that Tamura was attempting to enter the NFL offices, which are based at 345 Park Avenue.

However, the mayor added that the gunman accidentally entered the wrong set of lifts.

"We have reason to believe that he was focused on the NFL agency that was located in the building," he stated.

Tamura played football at high school as a running back, and was identified as a player with potential by his then-coach in a 2015 Los Angeles Times article.

He did not, however, go on to play in the NFL, according to his former team-mates.

Police released further details from Tamura's note, in which he referenced drinking 'a gallon of antifreeze'.

Former Pittsburgh Steelers guard Terry Long was determined to have committed suicide at the age of 46 in 2005 after he drank a gallon of antifreeze.

He was subsequently diagnosed with CTE. The disease can only be officially diagnosed through a post-mortem, though a number of athletes have reported symptoms consistent with CTE while alive.