MONROE — A 39-year-old Monticello man was sentenced to eight years in prison and six years of extended supervision after allegedly breaching the terms of his plea deal related to previous felony charges involving the sexual assault of 15-year-old girl in his downtown apartment. 

At a court hearing Sept. 26, Adam Kierna faced prison time not only for new drug possession charges but also for violations linked to a previous deferred prosecution agreement concerning a second-degree sexual assault of a child. 

“I do regret the decisions I made,” Kierna told Circuit Judge Jane Bucher prior to sentencing, in which the state sought a 10-year sentence. “I want to do better.”

This deferred prosecution was approved in court on Aug. 2. As part of his plea agreement, a separate charge of third-degree sexual assault was dismissed. 

The judge last Thursday cited Kierna’s lengthy criminal record, including convictions in Illinois, and the damage the abuse inflicted on the underage victim, for her decision on prison time.

“This case is unusual,” said Bucher. “(The) consequences she (the victim) suffered are astounding.”

Kierna’s road from probation was detailed by the district attorney. 

“Mr. Kierna was sentenced to five years of probation for Count 3, which involved an additional charge of third-degree sexual assault, requiring him to serve one year in the Green County Jail with Huber (work release) privileges,” District Attorney Craig Nolen said of the original sentence prior to the re-sentencing by Bucher. “Furthermore, Mr. Kierna entered into a Deferred Conviction Agreement for Count 1 (sexual assault) after pleading guilty, which is set to last for five years.”

On Dec. 7, 2023, Nolen added, the state filed a motion to vacate that Deferred Conviction Agreement and proceed to sentencing “on Count 1 of 2nd Degree Sexual Assault of Child…” A guilty plea and conviction also was entered on third-degree sexual assault, according to court records.

The new charges also were drug related and include felony possession of an illegal article — he allegedly tried to smuggle suboxone into Green County Jail — and felony possession of a controlled substance. 

Officials said the original crime happened around Thanksgiving in 2021 in downtown Monticello, but it did not come to light until later when the victim reported the crime to law enforcement officers nearly 1,000 miles away in Virginia. A statement was taken there on April 6, 2022.

That’s where the teen victim described the incident, in which she visited Kierna at his apartment above a shop in downtown Monticello. 

“One thing led to another and I ended up in his bed,” the girl told authorities, according to a criminal complaint.

Later, investigators would get a copy of text messages between the pair, discussing the alleged incident and planning a future rendezvous. At one point in the transcript, the defendant appears to acknowledge what he is doing is wrong in a text to the teen.

A minor cannot legally consent to sex in Wisconsin. The defendant’s initial arrest on the felony sex charges came during a shift of his job at a New Glarus restaurant.  

Wearing a black t-shirt, a bearded Kierna was immediately taken into jail custody after the Thursday hearing.