Officers found the bodies after getting a call about a possible fight in Chinatown around 2 a.m., CBS2's Christina Fan reports.
They found two victims near Bowery and Doyers Street. One victim was lying on the ground, unconscious and suffering from severe head trauma. He was pronounced dead at the scene.
The other victim, also suffering from head trauma, approached the officers when they arrived. He was taken to the hospital in critical condition.
Just a block over on East Broadway, police found three more victims. All three had suffered severe head trauma and were pronounced dead at the scene.
Two witnesses told officers that they saw a man wearing a black jacket and black pants repeatedly striking at least one victim in the head with a metal object before running down Doyer Street.
Officers began to search the area and found a man who matched the witnesses' description, carrying a metal pipe, near Mulberry Street and Canal Street. He was taken into custody without incident.
The suspected killer, 24-year-old Randy Rodriguez Santos, is also homeless according to police.
"The officers placed the male into custody and recovered the metal object without further incident," the NYPD's Stephen Hughes said.
Officers spent much of the day canvassing the neighborhood, street by street, looking for more potential victims.
It is believed the victims were sleeping when they were attacked.
Watch: Police Provide Update On Quadruple Murder In Lower Manhattan --
Simba Bossir says he saw one of the victims just hours before the attack.
"I was sitting down with one of them, right there on that bench, we were hanging out together," Bossie told CBS2's Nick Caloway.
When he came back in the morning,. he learned his friend had been murdered.
"Terrible, terrible. It's not easy to swallow pain. It's not easy. That could happen to me too."
Those who work in the area say there are a lot of homeless individuals and sometimes fights break out but never has there been this level of violence.
"But this is every day, all young kids, 25, 30 years old, they start drinking all night over here and throw things all over the place," said Nick P., a Lower East Side resident.
"It is very scary, you know, because I walk through here all the time, going to the library and everything," Lower East Side resident Carla Williams said.
Mayor Bill de Blasio reacted to the incident on Twitter, saying, "We're stunned and horrified by this senseless act of violence against the most vulnerable members of our community."
Police said they have not established a motive and they believe the attacks were random.
Anyone who saw anything suspicious in the area or has information regarding this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-8477 or for Spanish, 1-888-577-4782. Tips can also be sent to the NYPDTips Twitter account or submitted online at NYPDCrimeStoppers.com.
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