Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. The jail figures are from the Vera Institute of Justice's Incarceration Trends data. Every office link was opened and checked against the office's own site between September 23, 2026 and October 4, 2026.
Williamson County, Illinois, has about 67,000 residents (2024 Census Bureau estimate). A DUI arrest in Williamson County starts two cases, a criminal case in the Circuit Court of Williamson County and a license case before the Secretary of State, and leaves three records. This guide follows the arrest from the roadside to the court file and the driving record.
This guide covers the law, the arrest, booking, the court case, the license case, the records and common questions.
Related guides: Williamson County public records, Williamson County arrest records, Williamson County warrants, Williamson County inmate search, Williamson County criminal records, Illinois arrest records and Illinois inmate search.
The DUI Law in Illinois
In Illinois the offense is DUI, and the limit is 0.08.
Driving in Illinois is consent to a breath or blood test when an officer has cause to suspect DUI; the license case that follows a refusal or a failed test is run by the Secretary of State, separately from the criminal case.
Illinois sets no time limit on prior offenses: every earlier conviction counts toward a repeat charge.
Who Makes DUI Arrests in Williamson County
The Williamson County Sheriff's Office and the agencies that report for Marion, Herrin, Carterville, Johnston City, Cambria, Energy and one more cities make the DUI arrests in Williamson County.
The FBI's agency list also places one more agency in Williamson County: John A. Logan College (campus police).
Together, the five agencies in Williamson County with all twelve months of 2025 on file reported 2,793 arrests to the FBI that year, all offenses together; the FBI's count for Williamson County does not break DUI out.
Booking After a DUI Arrest in Williamson County
A driver arrested for DUI and kept in custody goes to the county jail, whichever agency made the arrest. The jail, run by the Williamson County Sheriff's Office, held about 160 people on an average day in 2023 by the Vera Institute of Justice's count and has a jail page SearchSystems verified at wcsheriff.com/corrections2.html, phone 618-997-6541. The Williamson County inmate search guide covers the jail in full.
The Court Case
A DUI charge from Williamson County is brought by the State's Attorney in the Circuit Court of Williamson County.
The State's Attorney's page SearchSystems verified is at williamsoncountyil.gov/states-attorney, phone (618) 998-2229.
The court records page SearchSystems verified for the county is at williamsoncountyil.gov/departments/circuit-clerk, phone (618) 997-1301.
Illinois has no single public index of every trial court case; each court's records are looked up through that court.
The License Case
A DUI arrest starts two cases: the criminal one above and an administrative one over the license, run by the Secretary of State. The driving record, kept by the Illinois Secretary of State, carries the result of both.
The Records a DUI Leaves
- The arrest report: from the agency that made the arrest, under the Illinois Freedom of Information Act.
- The court file: from the Circuit Court of Williamson County, kept by the Circuit Clerk.
- The driving record: from the Illinois Secretary of State.
More on each: Williamson County arrest records, Williamson County police reports and Williamson County court records.
Frequently Asked Questions
What is the DUI limit in Illinois?
0.08 percent blood alcohol.
Where is a DUI case from Williamson County heard?
In the Circuit Court of Williamson County, brought by the State's Attorney. The court records page SearchSystems verified for the county is at williamsoncountyil.gov.
Where is a person arrested for DUI in Williamson County held?
At the county jail, run by the Williamson County Sheriff's Office, if kept in custody.
Who handles the license after a DUI arrest in Illinois?
The Secretary of State, in an administrative case separate from the court case.
How long does a DUI count as a prior in Illinois?
There is no time limit; every prior conviction counts.
Is this the official Williamson County website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official county, court and state offices described above and does not hold records, charge for them or take requests.