NYPD officials said Abel Cedeno gave a statement following his arrest, saying the two people he allegedly attacked were throwing pencils and spitballs at him and he went to confront them.
During the confrontation, police said Cedeno stabbed Matthew McCree and Ariane Laboy in the chest with a knife. McCree died a short time later, and Laboy was rushed to the hospital in critical condition.
But investigators said this was the first time Cedeno had trouble with these particular boys. He told detectives he had had problems before the start of school that day, but not with the two he allegedly stabbed during his third period class.
"He said he was being harassed but that is about all he said," NYPD Chief of Detectives Robert Boyce said. "He didn't further describe other children in other classes he was having problems with."
Boyce said there doesn't appear to be any prior intervention at the school -- and that Cedeno didn't reach out to anybody at the school regarding any harassment.
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"It was teasing. He called it harassment, but only students, not these two," Boyce said. "And that's important to point out."
A family friend said the taunting was a result of Cedeno's perceived sexual orientation, and believe he felt like he had no way out other than to resort to violence.
Cedeno told police he bought the switchblade knife on the Internet two weeks ago, just to have a knife.
Following his arrest while being walked to a police vehicle, Cedeno mouthed the word "yes" when asked if he had been bullied. Watch that video here:
Police added that the teen's mother is currently in Puerto Rico and they're working with the suspect's older brother.
Cedeno is being held without bail. His attorney requested "medical attention, psychiatric evaluation and that he be placed on suicide watch."