Police are hunting for a suspected serial shooter who has opened fire on two homeless people in Soho Saturday, killing one of them, sources said.

The sinister spree began at 5 a.m., when a sleeping 38-year-old man was shot in front of 54 King St. by the unknown assailant, police said. That victim was expected to survive his injuries, they said.

About an hour later the shooter casually approached a man braving frigid temperatures and a winter storm in a green sleeping bag in front of 148 Lafayette Street, according to police surveillance video.

The suspect kicked the sleeping man, looked around to see if anyone was watching, then pulled out a gun and shot him at point-blank range in the head, the disturbing footage showed.

The victim died, and the hooded shooter, wearing all black with blue gloves, fled the scene, police said.

His bullet-riddled body was found still in his sleeping bag 12 hours later, they said.

Police were said to be canvassing the fashionable Manhattan neighborhood to see if any other people without homes were targeted by the deranged killer.

“I wouldn’t be surprised if there are more, and we don’t know yet,” one investigator said.