A gunman opened fire inside a high-rise corporate building in the heart of Manhattan on Monday evening, killing a New York City police officer and three other people, officials said. The suspected shooter acted alone and died from a self-inflicted gunshot wound, law enforcement officials told NBC News.

Five people, including a New York City police officer, died Monday in a Midtown shooting. Suspected gunman Shane Devon Tamura died of a self-inflicted gunshot wound, officials said.

NYPD Commissioner Jessica Tisch laid out a timeline of how Shane Tamura carried out his heinous attack on a Midtown skyscraper early Monday evening.

Mamdani wrote on X that he was "heartbroken" by an active shooting in Manhattan that left at least three people dead.

A lone gunman carrying an assault-style rifle opened fire at an office building in midtown Manhattan on Monday evening, according to police. The building, 345 Park Avenue, contains offices belonging to the National Football League,

The shooter who killed an NYPD officer and three civilians in Manhattan on Monday has been identified as Shane Tamura. NYPD commissioner Jessica Tisch says Tamura traveled cross-country from Nevada and has a history of mental health issues.

In the photos first shared online, Tamura was captured walking into 345 Park Avenue with an assault rifle in his hand while decked out in a suit.

New York Mayor Eric Adams says that multiple people were injured during gunfire in Manhattan. NBC News’ Erin McLaughlin described the chaos inside the skyscraper as office workers barricaded themselves from the shooter.

Organizers in New York and other major U.S. cities planned to protest outside ICE detention centers, immigration courts and federal buildings on Monday.

The gunman reportedly fled to the Park Avenue building that houses NFL headquarters before killing himself on the 33rd floor.