Four homeless men were found beaten to death in Chinatown early Saturday and a fifth was critically injured in a terrifying Lower Manhattan rampage, police said.

Sources identified the alleged killer to The Post as Rodriguez “Randy” Santos, who has 14 past arrests — including an assault charge from May.

The homicidal spree came to light as cops responded to a 911 call of an assault in progress on Bowery Street near Doyers Street in Chinatown at about 1:50 a.m. and found two homeless men with head trauma, cops said.

One man was pronounced dead at the scene, the other victim, 49, was taken to NewYork-Presbyterian Lower Manhattan Hospital in critical condition, authorities said.

Police searching the area then discovered three other victims around the corner on East Broadway, all with head trauma, authorities said.

The three were pronounced dead on the scene.

Two of those victims were found in front of a store on East Broadway, and the third was discovered across the street.

That’s when cops spotted the alleged killer — who was holding a three-foot-long, blood-covered metal object that appeared to be from a construction site, a source told The Post.

The tight-lipped 24-year-old was taken into custody at the scene, police said.