NEWYou can now listen to Fox News articles!
Four people are dead after a man stormed a Manhattan office building at the height of Monday’s rush hour, leaving authorities to determine how the events played out.
Shane Tamura, 27, of Las Vegas died by suicide after gunning down four people and wounding a fifth inside a building that is the headquarters of Blackstone and the NFL, according to authorities.
“Pure evil came to the heart of our city and struck innocent people,” Police Benevolent Association President Patrick Hendry said at a news conference.
OFF-DUTY NYPD OFFICER, FATHER OF 2 KILLED IN DERANGED GUNMAN’S MANHATTAN RAMPAGE
After the bloodshed, NYPD Commissioner Jessica Tisch provided a timeline of events that led to four deaths.
Saturday, July 26
An initial investigation indicates Tamura’s vehicle traveled across the country, crossing through Colorado on July 26.
Sunday, July 27
Tamura was employed at a Las Vegas casino, but did not show up to work on Sunday, according to Tisch. That same day, his car was recorded moving through Nebraska and Iowa.
Monday, July 28
At 4:24 p.m. Tamura’s car was spotted in Columbia, New Jersey, and authorities revealed he drove into New York City shortly after.
NFLPA REACTS TO ‘TRAGIC’ SHOOTING AT OFFICE BUILDING OF LEAGUE’S HEADQUARTERS: ‘SINCERE CONDOLENCES’
Just minutes before 6:30 p.m., security footage showed the man exiting a double-parked BMW while carrying an M4 rifle, subsequently crossing an outdoor plaza and entering the office building, located at 345 Park Ave. The building’s tenants include Blackstone and the NFL.
“I was surprised at how he was actually strutting across the plaza,” Pat Brosnan, a former NYPD detective and founder of national security company Brosnan Risk Consultants, told Fox News Digital. “Complete confidence, focused, calm — almost nonchalant. [He is] holding the gun loosely at his right side without a worry in the world.”
Around the same time the first shots rang out, authorities received numerous 911 calls reporting an active shooter inside the building.
NYC GUNMAN HAD GRIEVANCES AGAINST NFL, FOOTBALL AS SHOOTING LEAVES SEVERAL DEAD: REPORT
The man began firing, striking NYPD Officer Didarul Islam as he worked as a corporate security detail and a woman attempting to take cover behind a pillar in the lobby.
“He makes his way to the elevator bank, where he shoots a security guard who was taking cover behind the security desk,” Tisch said.
Another man was also shot in the lobby, according to the commissioner.
NYC SHOOTING: WHAT TO KNOW ABOUT SHANE TAMURA, GUNMAN WHO KILLED 4 INCLUDING NYPD COP IN MIDTOWN MANHATTAN
The shooter then called an elevator and allowed a woman to exit the elevator unharmed. He rode up to the 33rd floor of the building and proceeded to shoot and kill one person.
New York City Mayor Eric Adams suggested the shooter may have been targeting the NFL, but “appeared to have gone to the wrong bank and he ended up on the floor of Rudin Management.”
“You see on the video that he discharged the weapon several times,” Adams added. “And we must commend Rudin Management for the safety precautions that they have put in place, even a safe bathroom where you can lock it down with a bulletproof door. Some of the staffers used that.”
WATCH: NYC gunman may have received help prior to attack
After his rampage, the man walked down a nearby hallway and shot himself in the chest, the commissioner said.
Authorities located the shooter’s vehicle nearby and subsequently discovered a rifle case, ammunition, magazines and a revolver – which was legally purchased on June 12 – stashed inside, Tisch said. Medication belonging to the shooter was also found inside the car.
The shooter used an AR-15-style rifle he assembled using parts purchased with help from an associate, who is being questioned by police, according to Tisch.
ACTIVE SHOOTER REPORT PROMPTS MASSIVE POLICE RESPONSE IN MIDTOWN MANHATTAN BUSINESS DISTRICT
As law enforcement officials look to nail down the exact details surrounding the shooting, Brosnan suggests authorities are likely starting their investigation by combing through countless hours of surveillance footage in an attempt to retrace the moments leading up to the bloodshed.
“He double-parked his BMW, took the M4, strutted across the plaza and went in and unleashed holy hell throughout the building,” Brosnan said.
On Tuesday, Tisch revealed authorities were traveling to Las Vegas to search the shooter’s home and visit the gun store where he legally purchase a revolver using a Nevada concealed carry license.
Brosnan suggests authorities will seek security footage from toll booths, pit stops and other locations the shooter passed through while making his cross-country journey to New York City.
WATCH: Slain NYPD officer killed in Midtown Manhattan shooting had two children, third on the way
“But that’s part of a much broader, more comprehensive recreation of the story,” Brosnan told Fox News Digital. “The story being what led him to come to 345 Park Ave. with that weapon and drive to get across the country.”
SHOOTING AT NEVADA CASINO RESORT LEAVES MULTIPLE PEOPLE INJURED; SUSPECT IN CUSTODY
The footage, along with any evidence compiled electronically and from the crime scene, will play a key role in determining why the shooter carried out his plans.
“What was his motivation?” Brosnan wondered. “That’s what [authorities] will be looking for. So, the cameras will be a piece of that puzzle, but there were many pieces of the puzzle.”
In a press conference, Adams pointed to a note found alongside the shooter’s body that contained grievances about the NFL over an unconfirmed claim that he suffered from chronic traumatic encephalopathy.
The victims have been identified as Islam, security officer Aland Etienne, Blackstone executive Wesley LePatner and a Rudin employee. An NFL employee was hospitalized and in stable condition, and four others sustained minor injuries while attempting to flee.
The NYPD did not immediately respond to Fox News Digital’s request for comment.
“I don’t believe that there’s anything that could have prevented it,” Brosnan said. “If someone were to do precisely what he did — double-park their car, take a weapon out, strut 40 feet into a building and open fire — I mean, there could be triple the amount of officers in there, security and NYPD, and they probably could not have stopped it because of how quickly it unfolded and how random.”
The Associated Press contributed to this report.
