A 13-year-old has been arrested and charged in the stabbing death of Barnard College freshman Tessa Majors in a New York City park, according to multiple senior law enforcement officials.

The teen faces charges of second-degree murder, robbery and a weapons-related charge, the officials said. His specific role in the death was not immediately clear.

The juvenile was apprehended at about 11 p.m. Thursday, and as of Friday was not being charged as an adult.

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Investigators are seeking two other people whom they believe had a role in the attack.

"I am absolutely confident that any individuals involved in this terrible, heinous attack will be brought to justice and will be brought to justice quickly," New York City Mayor Bill de Blasio said Friday during a radio interview.

Majors, 18, was stabbed repeatedly in Morningside Park, not far from Barnard's campus, before 7 p.m. Wednesday, according to the New York Police Department.

"During the struggle, one of the individuals pulled out a knife and stabbed her several times," NYPD Chief of Detectives Rodney Harrison said Thursday. "She staggered her way up the street. One of the security guards saw her and called 911."

She was pronounced dead at a nearby hospital.

"We are devastated by the senseless loss of our beautiful and talented Tess. We are thankful for the incredible outpouring of love and support we have received from across the country," Majors' family said in a statement released Friday. "We would also like to express our appreciation for the efforts of the men and women of the NYPD, who continue to work diligently on this case."

Police were questioning two teens, with their guardians present, Thursday, but they were later released, according to the NYPD.

Investigators believed there were between one and three suspects, one of whom stabbed Majors, in what Barnard officials said was an attempted robbery.

A law enforcement source told NBC New York that a witness saw a group of people running from where Majors was found by a security guard. A text alert sent to Barnard students said one male suspect was wearing a green jacket and a hat.

A $2,500 reward is offered for anyone who provides helpful information in the case.

Students at Barnard, a women's college affiliated with Columbia University, gathered to mourn Majors Thursday night, and a memorial near Morningside Park continued to grow Friday morning.

"The passing of Tess Majors is an unthinkable tragedy that has shaken us to our core. We are all grieving, and trying to grasp the senseless tragedy that took Tess from us," Barnard College President Sian Leah Beilock said during Thursday night's gathering.

Beilock shared that when asked why she wanted to attend Barnard, Majors wrote: “As an avid feminist, I have striven towards bridging my community gender divide by being outspoken in my classes, taking an intensive course on social justice, and campaigning for a congressional candidate. I enjoy taking difficult classes and feel invigorated when forced outside of my intellectual comfort zone. I embrace the culture of positivity and growth at Barnard.”

"And Tess did — embrace the Barnard culture full on," Beilock said.

A vigil for Majors will be held Sunday at 4:30 p.m. in Morningside Park, Manhattan Borough President Gale Brewer announced Friday.

Majors, who was from Virginia, played in a band and had recently played her first gig in New York City, according to her Instagram. She graduated from St. Anne’s-Belfield School in Charlottesville this year before beginning at Barnard, according to an obituary in the Augusta Free Press, where she interned in spring.

Majors' former boss and the owner of the news outlet, Chris Graham, told NBC's Charlottesville affiliate WVIR that he was "stunned" to learn of her death.

"To me the greatest tragedy here is that the world won't get to see what she would have done — it may have been in music, it may have been in writing, and it may have been in something else," Graham said. "But she had a lot to offer the world and for it to be taken a way so tragically its a loss to her family and to everybody."