Officials said the 14-year-old had been taken into police custody on Friday evening for last December’s killing of Tessa Majors.
Another teenager has already been detained over the killing of the 18-year-old, who was a student at Barnard College.
New York City Police Commissioner Dermot Shea said on Saturday the 14-year-old had been charged with murder and robbery. He is currently being charged as an adult.
“We are confident that we have the person in custody who stabbed her,” Mr Shea said at a press conference. “And that person will face justice in a court of law.”
Majors was stabbed as she walked through Morningside Park early on the evening of December 11. She staggered up a flight of stairs to street level and collapsed in a crosswalk.
A criminal complaint released on Saturday described Majors as struggling on a landing with three people and screaming, “Help me! I’m being robbed”.
Officials said they have evidence from videotapes, witness identification and DNA evidence from Majors’ fingernail clippings linking the teenager to the crime.
The attack, two days before the start of final exams at the women’s college, anguished city residents because of its proximity to campus and its apparent randomness.
“This arrest is a major milestone on the path to justice for Tessa Majors,” said district attorney Cy Vance.
A 13-year-old who was arrested in December and charged as a juvenile with felony murder told detectives he was at the park with other youths but was not the one who stabbed Majors.
Majors, of Charlottesville, Virginia, played in a rock band and had told an editor from a newspaper internship in high school that she planned to take journalism classes in college.
Additional reporting by Associated Press