DuPage County State’s Attorney Robert Berlin and Roselle Chief of Police Robert Barreto announced today, Tuesday, December 23, 2025, that three teens have been charged with sexually assaulting a female classmate at a Roselle graduation party. Following his First Appearance Court hearing this afternoon, Judge Joshua Dieden granted the State’s motion to detain Kevin Niemiec, age 18, of the 700 block of E. Elaine Circle, Prospect Heights. Niemiec is charged with three counts of Criminal Sexual Assault, a Class 1 Felony.
Judge Dieden denied the State’s motion to detain Niemiec’s co-defendants pre-trial. Zachary Mascolo, age 18, of the 900 block of N. Beverly Lane Arlington Heights, appeared in First Appearance Court Monday afternoon, December 22, 2025, charged with two counts of Criminal Sexual Assault; and Jon Clary II, age 18, of the 1700 block of Ariana Drive, Bartlett, appeared in First Appearance Court this morning. The DuPage County State’s Attorney’s Office did not initially disclose the number of counts of Criminal Sexual Assault for Jon Clary II. As part of their conditions of pre-trial release, the Court ordered that Mascolo and Clary shall not possess or consume alcohol and they shall have no contact with the victim or her family.
On June 15, 2025, the Roselle Police Department was notified of a criminal sexual assault that had allegedly occurred at a Saint Viator High School graduation party in Roselle the night before. Following an investigation into the matter, it is alleged that at some point between June 14, 2025, and June 15, 2025, the defendants and the victim were in a minivan where each of the defendants sexually assaulted the victim. Following the assault, the victim went to the home of a friend, where she contacted her sister, who, in turn, told their parents. The victim’s parents immediately picked up the victim from the friend’s house and brought her to a local hospital for medical attention. On December 17, 2025, Judge Michael Burton issued an arrest warrant for all three defendants. On December 21, 2025, authorities took Mascolo into custody on his arrest warrant as he was driving near his home. Clary and Niemiec turned themselves in to the DuPage County Jail on December 22, 2025.
All three suspects were 18 years-old on June 15, 2025.
“The allegations levied against these defendants are extremely serious. 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. I thank the Roselle Police Department for their efforts on this very disturbing case as well as the DuPage County Sheriff’s Office Digital Forensic Investigation Unit for their outstanding work that enabled us to file today’s charges. I also thank Assistant State’s Attorney Jaclyn McAndrew for her work in securing strong charges against Mr. Clary, Mr. Mascolo and Mr. Niemiec.”
— DuPage County State’s Attorney Robert B. Berlin
“I commend the hard work and professionalism of the Roselle Police Department detective division. The detectives worked countless hours on gathering evidence in order to bring this case before the DuPage County States Attorney’s Office for charges. I want to give a special thanks to State’s Attorney Bob Berlin and Assistant State’s Attorney Jaclyn McAndrew, who worked on this case, as well as the DuPage County Sheriff’s Office Digital Forensic Investigation Unit who provided us with direction, assistance and support.”
— Roselle Chief of Police Robert Barreto
The next court appearance for Niemiec is scheduled for January 12, 2026, in front of Judge Ann Celine O’Hallaren Walsh. The next court appearance for Mascolo and Clary is scheduled for January 27, 2026, in front of Judge O’Hallaren Walsh.
Members of the public are reminded that this complaint contains only charges and is not proof of the defendants’ guilt. The defendants are presumed innocent and are entitled to a fair trial in which it is the government’s burden to prove their guilt beyond a reasonable doubt.
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