Dramatic surveillance and bodycam footage released by the NYPD captures the chaotic “Wild West”-style showdown on Manhattan’s Upper East Side Thursday evening, where officers gunned down a 20-year-old armed man after he menaced residents, threatened a mass shooting at a hospital, and opened fire on cops in a crowded street.

The suspect, identified as Elijah Brown, was pronounced dead at the scene after a frantic chase that spanned multiple blocks near Mount Sinai Hospital. No officers or bystanders were injured in the final exchange, though the incident left upscale neighborhoods reeling.

“It turned into the Wild West out here,” one eyewitness told The Post, describing the surreal scene as Brown casually strolled down Madison Avenue with a handgun dangling at his side, pursued by uniformed officers shouting commands.

The ordeal kicked off around 7 p.m. when Brown entered an elevator at 1590 Madison Ave., a residential building near East 96th Street. Video shows him pulling a silver semiautomatic pistol on an elderly man inside the elevator, who pleaded, “Please, no.”

Brown then stormed a nearby deli at 1600 Madison Ave., waving the gun at the clerk and demanding he call 911. “I’m going to the hospital to shoot it up,” Brown allegedly snarled, before snatching the worker’s phone and bolting.

Minutes later, he barged into Mount Sinai Hospital’s emergency room entrance, briefly ditched the weapon outside near a tree, then re-entered – only to encounter an off-duty NYPD officer working security. A scuffle ensued as the cop tried to detain him, but Brown broke free, retrieved his gun, and fled south on Madison Avenue.

That’s when all hell broke loose.

Surveillance clips show Brown sauntering down the sidewalk, gun in hand, as panicked pedestrians scattered. At least two uniformed officers gave chase on foot, yelling “Drop the gun!” repeatedly.

At East 95th Street, Brown suddenly whirled around and fired at the cops – prompting return fire that dropped him instantly. Sources say officers unleashed a barrage of rounds, striking Brown multiple times in the torso.

“This guy was calm as can be, like he didn’t have a care in the world,” said a deli worker who witnessed part of the rampage. “He pointed that thing right at me – I thought I was done.”

NYPD Chief of Patrol Philip Rivera praised the responding officers during a late-night presser. “Our cops ran toward the danger while everyone else ran away. This individual menaced innocent people, threatened a hospital shooting, and then fired at police on a busy street with civilians everywhere. Their actions prevented a tragedy.”

The recovered firearm – a loaded 9mm Glock with an extended magazine – was displayed by cops at the briefing. Ballistics tests are underway to determine if it matches any prior crimes.

Brown’s motives remain a mystery. Family members reached by reporters described him as troubled, with a history of mental health issues, but no prior arrests for violence. He lived in The Bronx and had recently been bouncing between relatives’ homes.

Mayor Eric Adams, a former cop himself, weighed in Friday morning: “Thank God our finest were there to stop this nightmare before it got worse. We back the blue – they saved lives yesterday.”

The shooting has reignited debates over mental health crises and gun access in the city. Advocacy groups like New Yorkers Against Gun Violence called for stricter laws, while while police unions defended the officers’ use of force.

“Look at the tape – the guy shoots first,” said Patrick Hendry, president of the Police Benevolent Association. “Our members don’t get paid to be target practice.”

Bodycam footage from the pursuing officers shows the tense pursuit up close: heavy breathing, commands blaring, then the crack of gunfire as Brown turns and blasts away.

One clip ends abruptly with an officer screaming, “Shots fired! Suspect down!”

The Attorney General’s office has launched a routine review of the officer-involved shooting, as required by state law. No cops have been placed on modified duty yet.

Meanwhile, the Upper East Side – typically a haven for the wealthy – was locked down for hours. Yellow tape cordoned off blocks, and shell casings littered the pavement.

Residents expressed a mix of relief and shock. “This is the kind of thing you see in movies, not on Madison Avenue,” said one shopper. “Those cops are heroes.”

At Mount Sinai, staff huddled in lockdown as the drama unfolded outside. “We train for active shooters, but when it’s real…” trailed off one nurse.

Brown’s body was removed under a white sheet as dawn broke Friday. His family has hired a lawyer and plans a private autopsy.

As the investigation continues, sources say detectives are poring over Brown’s phone and social media for clues. Was this a cry for help gone wrong? Or something more sinister?

One thing’s clear: In a split-second, NYPD officers turned a potential bloodbath into a contained incident – but at the cost of another young life lost to the streets.

The Big Apple breathes a sigh of relief, but questions linger. How did a 20-year-old get his hands on a high-capacity handgun? And why did he snap?

For now, the thin blue line held. But in today’s New York, every day feels like the Wild West.