Police said Randy Rodriguez-Santos, 24, who is homeless, wielded a 15-pound metal pipe and apparently attacked the men randomly.
He is charged with murder, attempted murder and unlawful possession of marijuana.
"The motive appears to be, right now, just random attacks," Chief of Manhattan South Detectives Michael Baldassano said, adding there was no evidence yet that the victims were "targeted by race, age, anything of that nature."
The victims were bludgeoned as they slept on the street. Their ages range from 48 to 83.
RELATED: Former homeless man leaves pizza at scenes of Chinatown murders
Police responded to reports of a dispute at Doyers Street and Bowery around 2:10 a.m. and found two men with head wounds. One victim was pronounced dead at the scene and another was taken to the hospital in critical condition.
Over the next hour, police discovered additional victims in the area: Two men were found outside of 2 East Broadway, and another was found outside of 17 East Broadway.
The weapon was recovered nearby.
Rodriguez-Santos was expected to make his first appearance in court Sunday.
Police say he has been arrested 14 times.
The identities of the victims have not yet been released. An investigation is ongoing.
Mayor Bill De Blasio tweeted that he's "stunned and horrified by this senseless act of violence against the most vulnerable members of our community."
A city lawmaker said more must be done to help the homeless population. "We make it so difficult for people to be able to get out of poverty," said Assemblywoman Yuh-Line Niou. "And our housing prices are increasing. It's getting more and more difficult to find affordable housing. You see that folks are struggling and I think that we need to be able to have a systemic change."
Anyone with information in regards to the above incident is asked to call Crime Stoppers at 1-800-577-TIPS (8477). The public can also submit tips by logging onto the Crime Stoppers website at WWW.NYPDCRIMESTOPPERS.COM or by texting their tips to 274637 (CRIMES) then enter TIP577.
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts