New York – A 27-year-old man wearing body armor and carrying an M4 assault rifle shot and killed four people, including an off-duty police officer, in a Midtown Manhattan office building Monday evening before killing himself, officials said.
A fifth victim was critically injured in the shooting, officials said. In a statement, NFL Commissioner Roger Goodell said that victim is one of its employees and was listed in critical but stable condition.
The shooting occurred just before 6:30 p.m. in an office building at 345 Park Ave. at East 52nd Street, which contains the headquarters for the investment company Blackstone and the National Football League, sources told ABC News.
The suspect, identified as Shane Tamura, carried a note in his pocket claiming he suffered from CTE, asked that his brain be studied and made references to the NFL, police sources told ABC News.
Police said he had a documented mental health history and played high school football.
The three-page note was described by sources as rambling and contained references to the NFL sources described as vague.

After barricading himself on the 33rd floor, Tamura, a Las Vegas resident, was found dead from what is believed to be a self-inflicted gunshot wound, according to New York Police Department Commissioner Jessica Tisch.
During a news conference Monday evening, Tisch said preliminary information suggests the suspect traveled cross-country in a BMW from Las Vegas before arriving in New York City.
Tamura had a license to carry a concealed weapon in the state of Nevada. “We believe this to be a lone shooter,” Tisch said.
Police say Tamura emerged from a double-parked BMW Monday evening with an M4 rifle.
A security camera image shows Tamura holding a long gun and walking outside the office building.
He entered the lobby of the Midtown tower alone and immediately opened fire on an NYPD officer and sprayed the lobby with bullets.
He made his way to the elevator bank, where he shot a security guard, Tisch said. He then went up to the 33rd floor, where he shot another person before shooting himself in the chest, she added.
Detectives are actively trying to determine why the suspect went to the 33rd floor – whether he specifically was headed there or if he simply wound up on that level. Rudin Management, the real-estate company, is located on that floor.
Officers searched the suspect’s vehicle after the shooting, where they found a rifle case with rounds, a loaded revolver, ammunition and magazines, a backpack, “and medication prescribed to Mr. Tamura,” Tisch said. He had a documented history of mental-health problems, Tisch said.
The motive is currently under investigation, FBI Deputy Director Dan Bongino said earlier on Monday.
In total, four people were shot dead plus the shooter in what Mayor Eric Adams called a “violent, despicable” act.
The deceased included NYPD officer Didarul Islam of the 47th Precinct, who came to the U.S. from Bangladesh and who Adams said he had been on the force almost four years. He was working security in the building while off duty.
“Early tonight, I met with the officer’s family. I told them that he was a hero, and we admire him for putting his life on the line,” Adams said.
Islam was married with two young boys, and his wife was pregnant with a third child.
The officer, and the surviving male civilian were taken to New York Presbyterian, where the civilian is in critical but stable condition.
Two other civilians, one male and female, both killed in the shooting, were taken to Bellevue Hospital. Police say another female was the victim found dead on the 33rd floor.
A witness inside the Midtown office building at the time of the shooting, detailed to NY Budgets what it was like at the scene as colleagues hid in lockdown, unsure of what was unfolding.

“The only thing between me and the door was a chair flipped over,” Jessica Chen said of the initial moments of the lockdown. “I texted my parents ‘I love them,'” she continued.
“Nothing can describe that feeling,” Chen added.
Chen went on to say that she recalled doing active shooter drills in school and said she often wondered what she would do in this kind of scenario. “It’s unfortunate that all Americans could think this through,” Chen said.
New York Gov. Kathy Hochul said she has been briefed on the situation.
KPMG, an accounting firm that also has offices in the building, released a statement after the shooting, saying, “Our hearts go out to the victims of this horrific act and their families.”
“We are incredibly grateful for the bravery of building security and law enforcement,” the company said.
Across the country, several squad cars from Las Vegas Metro Police have convened at entrances to the gated neighborhood where the purported suspect in the midtown Manhattan shooting was believed to have a home.
Detectives will be working throughout the night and the days ahead to piece together a profile of the man responsible.
Investigators are working to see where and when the gunman bought the high-powered rifle used in the rampage.
Detectives are now scrolling through thousands of surveillance cameras to pin point the gunman’s movements, minute by minute.