A young man was killed and another man was left in critical condition after a relentless gunman shot the pair several times on a Brooklyn street on Easter Sunday, according to harrowing surveillance footage and authorities.

Police discovered a 30-year-old man and a 50-year-old man riddled with gunshot wounds after they responded to reports of a shooting just before 6 p.m. outside a building on Fulton Street between Cleveland and Elton streets in Cypress Hills, according to the NYPD.

Both unidentified men were taken to Brookdale University Medical Center in critical condition. The 30-year-old was later pronounced dead, police said.

A person of interest in the shooting was also taken into custody, cops added.

Surveillance footage obtained by The Post captured two men standing on the sidewalk below the elevated J train subway platform near a group of about three men.

Moments after one of the men appears to say something to the crew, a man in a gray jacket and light pants whips out a gun and chillingly fires several shots at him and the other man he was standing near, according to the clip.

The shooter continued to pump bullets into the victims even as they lay motionless on the sidewalk, the disturbing footage showed.

One man dressed in dark clothing and white sneakers started walking away from the group the moment the shooter took out the gun.

Photos later captured stunned onlookers at the scene as authorities swarmed the area and marked a large number of shell casings.

It is unclear what sparked the gunfire or the men’s affiliation with each other. The investigation remains ongoing, authorities said.