A second teenager was arrested in connection to the fatal stabbing of a Barnard College student in a Manhattan park earlier this week, sources said Friday evening.

• Barnard College Community Reeling From Student's Death

The NYPD has been investigating the killing of 18-year-old Tessa Majors, whom police said was stabbed multiple times just before 7 p.m. Wednesday near West 116th Street and Morningside Drive.

Sources said two teenagers, ages 13 and 14, were charged Friday in juvenile court with murder, robbery, and criminal possession of a weapon (a knife). Their names will not be released because they are being charged as juveniles.

At this time, this is not considered a gang-related attack. The 13-year-old implicated himself in the attack, sources said.

It's unclear if police will make more arrests.

Investigators were trying to determine what led up to the attack.

Majors was completing her first semester at the school and was from Virginia. A Columbia University security guard found the victim and called 911, according to police. The woman was transported to Mount Sinai-St. Luke's Hospital, where she was pronounced dead.

Police said a knife was recovered at the scene, but it was still unclear if it was connected to her killing.

On the Barnard College campus, students were shaken and visibly upset as they gathered at a vigil for Majors, a writer and musician who played in a band.

In a statement to the press, her family said she was a light that shined brightly. Her death has also shaken the community at large.

"What Tessa's fatal stabbing and loss of life means, is that it could be any one of us," said Iesha Sekou, the founder of advocacy group Street Corner Resources.

Barnard College's president told students in a letter, "we are all grieving, and overwhelmed by the senseless tragedy that took Tess Majors from us."

The letter went on to say the NYPD will increase its presence around the campus, something many students say is needed.

"There should be lights in the park. Genuinely there should be lights. There should be 24/7 security guards. Personally when I go to the park, I almost never see a security guard," one student said.

Students told NY1 on Thursday night that more than a dozen lights in the park were out. Earlier in the day, we saw someone changing some of the lightbulbs.