Judge denies pretrial release for teen charged in graduation party sexual assault

A 19-year-old Prospect Heights man accused of sexually assaulting a former classmate during a graduation party in June should remain behind bars in the DuPage County jail while awaiting trial, a judge ruled Monday.

Kevin Niemiec is the only one of three recent St. Viator High School graduates charged in the case still in custody.

In rejecting a request he be freed, DuPage County Judge Ann Celine O’Hallaren Walsh said Monday that electronic communications obtained by investigators indicate Niemiec could be a threat to the accuser or public if released.

While his attorneys argued Niemiec believed the messages would always remain private, the judge called them “deplorable.”

Assistant DuPage County State’s Attorney Jaclyn McAndrew argued home confinement and GPS monitoring are not appropriate for Niemiec.

“He would have unfettered access to women,” McAndrew said during Monday’s court hearing. “You can’t prevent young women from entering his house.”

O’Hallaren Walsh said despite other information taken into account, like Niemiec’s lack of a prior criminal record, letters of support from family and friends as well as his volunteer and church-related history, she “completely concurs” with the initial detention ruling made in December 2025.

As part of their investigation, Roselle detectives sought electronic communications made on social media apps between the three suspects.

In one conversation, Niemiec wrote, “I will ruin every girl’s life I get with in revenge” for what his accuser “did to me.” He then wrote, “ALL OF FEMALE KIND WILL PAY FOR THIS,” according to court records.

While Niemiec’s attorneys argued being kept in jail is affecting his mental and physical health, McAndrew noted he had messaged friends as recently as February telling them he was “good physically” and “mentally OK.”

Niemiec and co-defendants Jon Clary II of Bartlett and Zachary Mascolo of Arlington Heights, are charged with criminal sexual assault, criminal sexual abuse, kidnapping and unlawful restraint. They have all pleaded not guilty.

Clary and Mascolo, both now 19 as well, previously were granted pretrial release.

Prosecutors allege the trio assaulted an 18-year-old female former classmate inside a minivan parked near a Roselle home that was hosting a graduation party on June 14. The minivan belonged to Niemiec’s mother.

The woman told police she was able to escape only after friends found her inside the van. She told her friends and parents what happened, and she was taken to a hospital a few hours later for treatment.

Police collected DNA evidence from both the woman’s clothes and the minivan, according to court papers.

After receiving DNA results, Roselle police secured arrest warrants for the three men, who were all 18 at the time.

Niemiec’s next court appearance is scheduled for April 15.