3 teens plead not guilty in alleged sex assault of classmate at suburban high school grad party

WHEATON, Ill. (WLS) -- Two former Saint Viator High School students accused of sexually assaulting a female classmate have pleaded not guilty.

Zachary Mascolo of Arlington Heights and Jon Clary of Bartlett were in court Tuesday.

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They both face multiple felony charges tied to an alleged assault at a graduation party in Roselle last June.

Prosecutors say it happened inside a minivan parked near the party.

A third teen, Kevin Niemiec of Prospect Heights, is also facing charges.

He pleaded not guilty earlier this month, and is in custody at the DuPage County Jail.

"The allegations levied against these defendants are extremely serious," DuPage County State's Attorney Robert Berlin previously said. "A graduation party is a celebration of accomplishments and the excitement of a bright future. It is alleged that Mr. Clary, Mr. Mascolo and Mr. Niemiec violated the victim in the worst possible way and inflicted a lasting harm on a young woman. It is my sincerest hope that the victim and her family receive the care they require and deserve to help them cope with this horrific event. I commend the victim in this case for her courage and strength in bringing this matter to our attention."