A gunman who killed four people at a Manhattan office building before killing himself was trying to target the headquarters of the NFL but took the wrong elevator, officials said Tuesday.
Investigators believe Shane Tamura, a 27-year-old Las Vegas casino worker, was trying to get to the NFL offices after shooting several people Monday in the building's lobby but accidentally entered the wrong set of elevator banks, New York City Mayor Eric Adams said in interviews.
Four people, including off-duty New York City police officer Didarul Islam, were killed. Tamura, who played high school football in California roughly a decade ago but never in the NFL, had a history of mental illness, police said.
A three-page note found in Tamura's wallet suggested he had a grievance against the NFL over a claim that he suffered from chronic traumatic encephalopathy. The degenerative brain disease has been linked to concussions and other repeated head trauma common in contact sports such as football, but it can be diagnosed only after someone has died.
In the note, Tamura repeatedly said he was sorry and asked that his brain be studied for CTE, according to the police department. The note also referenced former NFL player Terry Long, who was diagnosed with CTE, and the manner in which Long killed himself in 2005. The note accused the NFL of concealing the dangers to players' brains for profit.
The New York Post reported Tuesday that the note also mentioned "League of Denial," a PBS documentary about concussions in the NFL, and the "Fainaru Brothers," an apparent reference to ESPN reporters Mark Fainaru-Wada and Steve Fainaru, who wrote a book released alongside the documentary. It also mentioned several prominent doctors who have studied concussions.
The NFL long denied the link between football and CTE, but it acknowledged the connection in 2016 testimony before Congress and has paid more than $1.4 billion to retired players to settle concussion-related claims.
Asked whether Tamura would be tested for CTE, Adams told CNN that the city's medical examiner would make that determination.
In response to ESPN, the medical examiner's office said: "The medical examiner is investigating and will share the cause and manner of death when available. An examination of brain (neuropathology) is part of the complete autopsy process."
NFL commissioner Roger Goodell called the shooting "an unspeakable act of violence in our building," saying he was deeply grateful to the law enforcement officers who responded and the officer who died protecting others.
Goodell said in a memo to staff that a league employee was seriously injured in the attack and was hospitalized in stable condition.
Goodell added that there would be an "increased security presence" at the league's offices "in the days and weeks to come." He later said employees based in New York should work remotely "at least" through Aug. 8 and "the office will remain closed during this time" until "we confirm that [the building] is ready for us to return."
"Every one of you is a valued member of the NFL family," Goodell said. "We will get through this together."
The shooting happened at 345 Park Avenue, one of the nation's most recognized streets, and just blocks from Grand Central Terminal and Rockefeller Center. It's also less than a 15-minute walk from where UnitedHealthcare CEO Brian Thompson was shot and killed last December by a man who prosecutors say was angry over corporate greed.
New York Giants coach Brian Daboll and Atlanta Falcons coach Raheem Morris opened their remarks by referencing the shooting.
"You all saw what happened there at 345 Park -- tragic," said Daboll, who added that he had not had any conversations with Giants players or staff about the situation.
"Just want to start out addressing the senseless violence that happened in New York," Morris said. "Just send our thoughts and prayers to everybody involved, including one of our own."
President Donald Trump said Tuesday that he knows that area of Manhattan well.
"I trust our Law Enforcement Agencies to get to the bottom of why this crazed lunatic committed such a senseless act of violence. My heart is with the families of the four people who were killed, including the NYPD Officer, who made the ultimate sacrifice," Trump posted on social media.
Investigators found that Tamura, who worked security at the Horseshoe Las Vegas but failed to show up for his shift Sunday, drove across the country over the past few days and made his way into New York City just before the shooting, Police Commissioner Jessica Tisch said.
Tisch added Tuesday that investigators plan to question a man who supplied parts for the gun used in the attack. The AR-15-style rifle was assembled with parts, including a lower receiver, that were purchased by an associate, according to Tisch.
Police have located that associate and will be questioning him about a purchase, she said.
Surveillance video showed the gunman exiting a double-parked BMW at about 6:30 p.m. ET Monday evening with a rifle, then marching across a plaza and into the skyscraper, which is also home to investment firm Blackstone and other companies.
Tamura then sprayed the lobby with gunfire, killing Islam, who was off police duty and working a corporate security detail, and hitting a woman who tried to take cover, Tisch said. He next made his way to the elevator bank, shooting a guard at a security desk and another man in the lobby, the commissioner said.
"He appeared to have first walked past the officer and then he turned to his right, and saw him and discharged several rounds," Adams said in a TV interview.
NFL employees were told to shelter in place at the time, according to ESPN's Jeff Darlington. The NFL offices are on the fifth through eighth floors of the 44-story building.
Tamura took an elevator to the 33rd-floor offices of the company that owns the building, Rudin Management, and shot and killed one person on that floor. He then shot and killed himself, the commissioner said.
Blackstone confirmed that one of its employees, real estate executive Wesley LePatner, was among those killed. Julia Hyman, who worked as an associate at Rudin Management, and security officer Aland Etienne were also killed, according to the City of New York Office of Chief Medical Examiner.
"Words cannot express the devastation we feel," Blackstone said in a statement. "Wesley was a beloved member of the Blackstone family and will be sorely missed. She was brilliant, passionate, warm, generous, and deeply respected within our firm and beyond."
Islam was a 36-year-old immigrant from Bangladesh who had served as a police officer in New York City for 3½ years, Tisch said at a news conference. His body was draped in the NYPD flag as it was moved from the hospital to an ambulance, with fellow officers standing at attention.
His flag-draped remains arrived later Tuesday afternoon at the Bronx mosque preparing for his funeral.
"He was doing the job that we asked him to do. He put himself in harm's way. He made the ultimate sacrifice," Tisch said. "He died as he lived: a hero."
Adams visited the scene later in the day and recalled working in the mailroom of the building as a young man.
"To have to walk through and see the remnants of violence at that level, tore at me," he told mourners at an evening multifaith vigil for those killed.
Muslim, Sikh, Buddhist, Hindu, Christian and other faith leaders delivered prayers at the gathering held at a park about a dozen blocks from where the shooting took place.
Adams said one challenge of the investigation has been that Tamura arrived in New York only shortly before the shooting, leaving few clues in the area.
"We are going to communicate with federal and state partners in Las Vegas to drill down on this as much as possible including looking at his social media pages, anything that he may have in his home, so that we can continue to piece this investigation together," Adams said.
The Associated Press contributed to this report.