Rigoberto Lopez, 21, was taken in to custody reportedly drenched in blood before being charged in connection with the deadly stabbings.
The four unprovoked attacks apparently targeted homeless people and took place on the A train or at stations served by it beginning on Friday morning.
Local radio station 1010WINS, citing police sources, said Lopez was taken into custody late on Saturday wearing blood-soaked clothes and shoes.
Police said on social media that Lopez was found with a knife at the time of his arrest "which he used on the vulnerable".
Outlining events, police said that after the first attack a 67-year-old man is still recovering in hospital after being stabbed by a masked attacker at a station in upper Manhattan.
Hours later, another man was found stabbed to death on an A train at Far Rockaway-Mott Avenue station in Queens.
Soon after, a 44-year-old woman was found unconscious and with stab wounds on an A train at the 207th Street station in Manhattan.
She was pronounced dead in hospital.
The fourth alleged victim was a 43-year-old man who was stabbed early on Saturday, also at the West 181st Street station.
After undergoing surgery, he was in a stable condition, and not likely to die, police said.
New York City Police Commissioner Dermot Shea told reporters on Saturday that 500 additional officers had been deployed to the city's transit system "to make sure people feel safe."
In the televised briefing he said the force offered condolences to the victims' families.Follow the Official Rokna NEWS Telegram Channel For More and fresh NEWS.