A New York Police Department officer and three civilians were shot and killed Monday evening, with another civilian alive and in critical condition, after a gunman opened fire at a Park Avenue office tower in Midtown Manhattan. The suspected gunman's name is Shane D. Tamura, a source familiar confirmed to the Washington Free Beacon.

The same source told the Free Beacon that the NYPD officer killed was a Bangladeshi immigrant to the United States.

The NYPD had the situation contained within about an hour of the shooting, police commissioner Jessica Tisch said in a statement posted on X.

Police took two other individuals into custody—a woman and a man who had been screaming "Free Palestine"—according to AM New York.

"This guy, he comes out of here ... he keeps saying, free Palestine," one bystander said. "He got his face covered up in the Palestine stuff."

The 44-storey building at 345 Park Ave is home to both the NFL and financial giant Blackstone.

"The FBI is on scene at the Manhattan crime scene," FBI deputy director Dan Bongino said in an X post. The NYPD currently has the lead in this investigation. Our personnel are there to support their efforts. Motive is currently under investigation."

Video taken by a local Fox affiliate showed several police officers carrying an injured man and applying chest compressions.

CNN speculated that the alleged gunman was white, a claim contradicted by a photo of the suspect confirmed by the source who spoke with the Free Beacon.

This is a developing story and will be updated.