A prosecutor said he is narrowing the timeframe on an indictment that accuses a former Wonder Lake grocery store owner and ski team instructor of sexually abusing a child.

Allan J. Mrowka, 70, is charged with aggravated criminal sexual abuse of a child younger than 13, a Class 2 felony, according to McHenry County court documents.

As usual, a group of about 10 supporters of the person Mrowka is accused of abusing a recent hearing. Some wore matching T-shirts that said, “Support squad sexual assault awareness.” Mrowka is not charged with sexual assault.

Mrowka’s attorney has filed a motion arguing that the four-year range prosecutors cite for when the alleged offense occurred – sometime between May 4, 1993, and May 4, 1997 – is too broad.

In response, Assistant State’s Attorney William Bruce said he is amending the indictment.

The indictment will now allege that the offense occurred on or between May 4, 1996, and July 30, 1997, Bruce said.

Defense attorney Damon Cheronis did not object.

In 2023, almost 30 years after the alleged abuse, Mrowka was arrested in Florida, where he was building a home and wintering. At his initial court appearance in McHenry County in late 2023, prosecutors said the former Wonder Lake grocery store owner “grabbed the buttocks” of the minor while helping him out of a boat. At the time, Mrowka was an instructor with the Wonder Lake Ski Team and the accuser was on the ski team, according to court documents.

His accuser went to police decades after the alleged abuse, according to court records.

The man ”contacted the police to describe an event that allegedly occurred some three decades prior when he was around 10 years old,“ according to a motion filed by Mrowka’s defense attorney.

Prosecutors said that the McHenry County Sheriff’s Office received 10 different reports from other people on the ski team of sexual abuse by Mrowka. However, he has not been charged in connection with those claims because of the statute of limitations, authorities have said.

In 1984, Mrowka pleaded guilty to one count of contributing to the sexual delinquency of a minor in McHenry County and received probation, prosecutors said.