"We believe this argument has been going on for about two weeks into the school year", NYPD Chief of Detectives Robert Boyce said. It started with "back and forth" between the three students and escalated.
A pen fight prompted Cedeno to attack his classmates, according to a witness, who told the New York Post that one of the victims was throwing pens across the room during class and the accused was hit by a pen.
Unlike other schools, the Urban Assembly School for Wildlife Conservation did not have screenings prior to the stabbing. It houses P.S. 67 as well as in the Urban Assembly School for Wildlife Conservation, which serves 6th through 12th graders.
The morning after a deadly stabbing at a Bronx public school, students from Pre-k to high school will be subject to much tighter security. He has preliminarily been charged with one count of murder, two counts of of attempted murder, one count of manslaughter, one count of attempted manslaughter, two counts of assault, and two counts of criminal possession of a weapon.
Abel Cedeno, 18, pulled out the $30 switchblade during third-period history class and plunged it into the chests of McCrae and Ariane Laboy, 16, police said.
'This tragedy should never have taken place, ' she said.
The other, Laboy's close friend, 15-year-old Matthew McCree, who police said was killed after also being stabbed in the chest.
Cedeno walked out of the classroom where he stabbed the boys, handed his Schrade switchblade to a counselor in the hallway and walked to the assistant principal's office to wait for police, officials said.More news: Most states see gas prices fall
"Two of my students got stabbed and one of them died", Kevin Sampson, the school's dean, told The New York Times.
WABC-TV identified the deceased student as Matthew McCree, 15.
Denise Jackson, the mother of a high school freshman, said she was terrified.
The stabbing has left concerned parents shocked and wondering why metal detectors were not present in the schools. The school building does not have metal detectors, but the mayor said there would be random checks with metal detectors starting Thursday. Ahmed Nasser, a police spokesperson said.
The father rushed to the school, where he saw his daughter, a kindergartener, through a window waving to him.
"I have been a staunch opponent of age-inappropriate co-locations throughout my tenure as borough president", said Bronx Borough President Ruben Diaz in a statement.
"I tried to called the school".