Another major development in a murder that shocked the city: police charged a third teenager in the stabbing death of 18-year-old Barnard College student Tessa Majors.

A 14-year-old was brought into court in handcuffs Wednesday. Prosecutors allege he stopped Majors from escaping the attempted robbery that led to her death.

The teenager stood along side his middle school classmate, 14-year-old Rashaun Weaver, who police believe actually stabbed Majors when she would not give them her cell phone. Both are being charged as adults, according to authorities.

Prosecutors say the pair and a 13-year-old, who is being charged in family court as a juvenile, tried to rob Majors as she cut through Morningside Park in December. Majors called out for help, police say.

“Some of the last words she was known to have said, was help me, I am being robbed,” Manhattan District Attorney Cyrus Vance said.

Prosecutors say Majors managed to break free and run up some stairs, but one of the teenagers caught her on a landing and held her in what Manhattan prosecutor Matthew Bogdanos called a "bear hug" or "headlock."

Prosecutors say Majors freed herself again, but by then, it was too late; she had been stabbed four times, and had just minutes to live.

In successfully asking for the teens to be held without bail, Bogdanos said the encounter was unusally long, lasting for more than a minute as Majors repeatedly tried to escape and get help.

"This isn't a spur of the moment, momentary, few seconds attack." Bogdanos said

The death of the Barnard freshman, who was from Virginia, unsettled the city. Her father, Inman Majors, was in court for the arraignment but did not speak afterward.

Both teens being tried as adults pleaded not guilty to the murder and robbery charges, and both defendants will be back in court on April 7.