NORTH MIAMI, Fla. – Four former students at North Miami Senior High School face felony sexual assault charges after allegedly gang raping a mentally disabled student in a janitor's closet, the Miami Herald reported.

Derek Bynum, 18, Kenoldo Alexis, 17, David Lombard, 17, and Steven Joseph, 15, were arrested in the case. Lombard also faces a charge of battery.

A fifth student was arrested, but prosecutors dropped the charges against him.

According to the newspaper, the teens forced the girl to perform oral, anal and vaginal sex acts in January.

Court documents show that Bynum told police that he didn't know the teen was mentally disabled, but admitted to forcing her to perform oral sex. Police said Bynum told the victim to stop "because she did a terrible job."

Bynum later wrote a letter to the judge to claim his innocence and apologize.

"All I want to do is graduate from high school, make my family proud and be somebody. But, this case, I feel like it will ruin my chances and my dreams," Bynum wrote, in part. "I'm sorry. I'm really a good kid."

The teens were assigned to alternative schools after the allegations were brought to police.

"The safety and security of our students and staff represent one of our top priorities," Miami-Dade County Public Schools spokeswoman Daisy Gonzalez-Diego said. "While we struggle to understand the senseless depravity of this isolated but disturbing student incident, we commend the deliberate and swift actions of Miami-Dade Schools Police in apprehending the alleged perpetrators. Our thoughts continue to be with the victim and her family. While it is nearly impossible to prevent isolated incidents, a clear understanding and review of all surrounding circumstances is undertaken to further perfect safety and security protocols."

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