Four people were killed when a gunman stormed into a New York City skyscraper at the end of the business day on Monday. 

An off-duty New York City Police Department (NYPD) officer, a security guard, a Blackstone executive and a Rudin employee were fatally wounded at 345 Park Avenue at 52nd Street in Midtown Manhattan.

Authorities said Monday night that a fifth victim had been shot and was hospitalized in critical but stable condition. 

The accused gunman – identified as 27-year-old Shane Tamura – died of a self-inflicted gunshot wound on the 33rd floor of the building, according to police. 

The building houses offices for the Blackstone Group, the National Football League (NFL), Rudin Management Company and “Big Four” accounting firm KPMG, among other businesses. The motive remains under investigation. 

Authorities said Tamura was a Las Vegas resident who last worked an overnight security job at Horseshoe Las Vegas. New York City Mayor Eric Adams told Fox News that NYPD teams are traveling to Las Vegas to conduct a search warrant on Tamura’s home and determine how Tamura obtained the AR-15-style rifle used in the shooting. Investigators believe Tamura assembled the gun using a lower receiver purchased by “an associate.” 

Aland Etienne

The Service Employees International Union (SEIU) identified one of its members, Aland Etienne, as one of the shooting victims killed. The union remembered Etienne as “a dedicated security officer who took his job duties extremely seriously.” 

Aland Etienne was identified as one of the four victims of the New York City office building shooting. (Facebook)

“We have been in touch with Aland Etienne’s family and are working with building management and the NYPD to support their investigation,” 32BJ SEIU, which is the largest property service workers’ union in the country, said in a statement. “We are ensuring our members in the building receive the free union counseling and support services they deserve and need to manage this unspeakable loss.” 

“This tragedy speaks to the sacrifice of security officers who risk their lives every day to keep New Yorkers and our buildings safe,” the union added. “Every time a security officer puts on their uniform, they put their lives on the line. Their contributions to our city are essential, though often unappreciated. Aland Etienne is a New York hero. We will remember him as such.” 

Etienne’s brother, Gathmand Etienne, also released a statement on social media. 

“My family suffered a heartbreaking tragedy. My brother, Aland, lost his life in the shooting that happened in New York while he was at work,” he wrote on Facebook. “He was more than a brother – he was a father, a son, and a light in our lives. Our hearts are shattered, and we’re asking for your prayers and strength as we navigate this painful time.”

“Rest in peace, Brother. You’ll never be forgotten,” he added. 

Aland Etienne died from a New York City office building shooting while working as a security guard. (Facebook)

Rudin Employee

Rudin Management Company said that one of its employees – reportedly a graduate of Cornell University just five years out of college – was killed in the shooting. Her family has asked for privacy. 

“The Rudin family and everyone at our company are devastated by yesterday’s senseless tragedy. Our thoughts and prayers are with those injured and lost last night, including our cherished Rudin colleague, a brave New York City police officer, a beloved lobby security guard and an employee at a tenant firm,” the company said in a statement. “We are grateful to the NYPD, FBI, EMS and multiple other emergency responders for their swift and courageous action.”

The company also thanked the mayor and the police commissioner for “their leadership” and said the building would remain closed Tuesday as the authorities continue their investigations. 

“As New Yorkers, we stand shoulder to shoulder in the face of this hatred, we grieve with the families and loved ones of those lost, and we pray for the full recovery of those injured,” Rudin added. 

At a press conference Monday, the NYPD commissioner detailed how multiple 911 calls came in at approximately 6:28 p.m. to report an active shooter inside 345 Park Avenue. 

Tamura exited a double-parked black BMW with Nevada plates on Park Avenue between 51st and 52nd streets, carrying an M4 rifle in his right hand, Tisch said. The building’s security camera footage showed the gunman enter the lobby, turn right, and immediately open fire on an NYPD officer. He then shot a woman who took cover behind a pillar and proceeded through the lobby, spraying it with gunfire, according to the police commissioner. 

A gunman with a weapon outside a midtown Manhattan building where multiple people were shot on Monday.  (Obtained by New York Post)

Video shows him making his way to the elevator bank, where he shot a security guard who was taking cover behind a security desk, police said. Tisch said an additional male – the hospitalized survivor – was shot in the lobby. 

Police said the shooter then called the elevator, which opens in the lobby. “A female exited that elevator, and he allowed her to walk past him unharmed,” Tisch said. 

The shooter then went to the 33rd floor, where Rudin Management is located, and began to walk around and fire rounds. One person was struck and killed on that floor, police said. 

Tisch said the gunman proceeded down a hallway and shot himself in the chest. 

Investigators believe Tamura’s vehicle traveled cross-country through Colorado on July 26, then through Nebraska and Iowa on July 27. The vehicle was spotted in Columbia, New Jersey, around 4:24 p.m. Monday before it entered New York City. 

Tisch said law enforcement partners in Las Vegas reported that Tamura had “a documented mental health history.” 

Adams said investigators were analyzing a suicide note in which Tamura expressed his belief that he experienced chronic traumatic encephalopathy, or C.T.E., and voiced grievances with the NFL.

Tisch said the gunman allegedly wrote “study my brain” in the note. Adams said that Tamura likely wanted to target the NFL office but took the wrong elevator bank. Tamura played football in high school in Los Angeles County but never in the NFL. 

Fox News’ Brooke Taylor, Leonard Balducci and Terrence Kenny contributed to this report.