A man has been taken into custody after allegedly killing three people in an apparent unprovoked stabbing spree in Manhattan, authorities said.

Ramon Rivera, an undomiciled man of 51 years old, was charged on Monday with three counts of murder in the first degree, according to the New York Police Department.

The first victim, a 36-year-old man who has been identified as Angel Lata Landi, was fatally stabbed in the abdomen at 8:22 a.m. Monday in an unprovoked attack by the construction site where he was working on West 19th Street, the NYPD said.

About two hours later, a 68-year-old man was fatally stabbed multiple times on East 30th Street, police said. The identity of the deceased has not been released, pending family notification.

The third victim, a 36-year-old woman, was picked up around 10:55 a.m. at 42nd Street and First Avenue, police said. She had multiple stab wounds in the chest and arm, and she was taken to New York Presbyterian/Weill Cornell Medical Center, where she later succumbed to her injuries.

The 51-year-old suspect -- who was staying at the Bellevue Men's Shelter on East 30th Street -- appeared to pick the victims at random, police said.

He was apprehended around East 46th Street and 1st Avenue, police said.

"He just walked up to them and began to attack them with the knives," Chief of Detectives Joe Kenny said at a news conference.

The suspect has eight prior arrests, according to law enforcement, and is believed to have severe mental health challenges, Mayor Eric Adams said.

"There’s a real question as to why he was on the street," Adams said.

Two bloody kitchen knives have been recovered, police said.

"These random attacks left two innocent victims dead and another fighting for her life," Kenny said. "We do have a suspect in custody and we are not looking for any others at this time."