Crystal Lake man pleads guilty to armed robbery, sentenced to 11 years in prison

Inset of Dieter Bierwirth Jr. in front of Northwest Herald file photo of McHenry County courthouse.

A 54-year-old Crystal Lake man appeared to be steadily shuffling his feet as he pleaded guilty Thursday to wielding a knife at a gas station employee while stealing a cash register containing less than $500 in 2020.

After accepting Dieter M. Bierwirth’s guilty plea to Class X armed robbery without a firearm, McHenry County Judge Robert Wilbrandt sentenced the man to 11 years and six months in prison.

Bierwirth, who shortly after his arrest was deemed mentally unfit to stand trial, said “yes, sir” when Wilbrandt asked if he understood what he was pleading to and the terms of sentencing.

Based on a psychological evaluation submitted by Illinois Department of Human Services, Wilbrandt ruled that Bierwirth was restored to fitness at a hearing in early December.

In exchange for his guilty plea, additional charges of unlawful possession of a controlled substance, theft under $500 and burglary were dismissed.

He will receive credit for 427 days in the McHenry County jail and for any additional days until he is transported to Illinois Department of Corrections. He is required to serve his prison sentence at 50%, the judge said. Bierwirth had faced up to 30 years in prison.

About 1 a.m. Nov. 1, 2020, police responded to a call at the Marathon gas station at 770 S. Virginia Road for an armed robbery.

The clerk said a man entered the gas station and held a large knife to his neck, threatened him and demanded money, Crystal Lake police said. He then forcefully took the cash drawer and fled the business on foot.

No injuries were reported.

Later that day, police returned to the gas station in response to another call from the clerk saying he thought a customer in the store was the same person who committed the robbery about 12 hours earlier.

The man fled on foot from the gas station, and Bierwirth was subsequently arrested by police. Police obtained a warrant to search Bierwirth’s home where they found items connecting him to the robbery, police said.

He has a past criminal history with convictions in Kane and McHenry counties including robbery, residential robbery, mob action, driving under the influence and telephone harassment, according to a motion filed by prosecutors.

Bierwirth’s defense attorney George Kililis said the crime was committed as the result of his drug addiction. Wilbrandt agreed and said he will recommend Bierwirth be enrolled in an alcohol and substance abuse program while in the custody of IDOC.

When asked if he had anything to say, Bierwirth said “No, sir.” As he was led away to the jail, he said, “Thank you, judge. Have a good day. I appreciate it.”