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), and arrests there are reported to the FBI by the Williamson County Sheriff's Office, seven city agencies and one campus agency. An arrest leaves the same records whoever makes it: the arresting agency's report, the record of anyone held at the county jail, and, if the State's Attorney files charges, a case in the Circuit Court of Williamson County. This guide says who keeps each one, what it costs and who may see it, with the arrest counts each agency reported.
This guide covers who makes arrests, how many arrests, booking and the jail, finding an arrest, copies, cities and common questions.
Related guides: Williamson County public records, Illinois arrest records, Illinois inmate search and Illinois criminal records.
Who Makes Arrests in Williamson County
The Williamson County Sheriff's Office is the county agency that reports arrests to the FBI for Williamson County. It reported 0 arrests for 2019, its latest complete year.
The FBI lists seven cities in Williamson County with a reporting agency of their own, with the Census population and what each reported:
- Marion, 17,021 residents: 1,076 arrests reported for 2025.
- Herrin, 12,253 residents: 487 arrests reported for 2025.
- Carterville, 5,821 residents: 55 arrests reported for 2025.
- Johnston City, 3,309 residents: 1,152 arrests reported for 2025.
- Cambria, 1,793 residents: 0 arrests reported for 2020.
- Energy, 956 residents: 23 arrests reported for 2025.
- Hurst, 750 residents: 0 arrests reported for 2019.
A city on that list is reported separately whether the officers are the city's own or the sheriff's under contract; the FBI's list does not say which.
The FBI's agency list also places one more agency in Williamson County: John A. Logan College (campus police).
How Many Arrests Each Agency Reports in Williamson County
Each agency reports its arrests to the FBI by month, and the FBI publishes them on the Crime Data Explorer. These are the full-year totals, all offenses, as the FBI held them on October 8, 2026; a year with months missing or not reported is left out.
- Johnston City: 1,152 for 2025, 1,152 for 2024, 1,146 for 2023, 1,132 for 2022, 919 for 2021 and 1,146 for 2020.
- Marion: 1,076 for 2025 and 1,113 for 2024.
- Herrin: 487 for 2025, 564 for 2024 and 393 for 2023.
- Carterville: 55 for 2025.
- Energy: 23 for 2025, 0 for 2020 and 0 for 2019; 2021, 2022, 2023 and 2024 are missing months.
- Hurst: 0 for 2019.
- Williamson County Sheriff's Office: 0 for 2019.
- Cambria: 0 for 2020 and 0 for 2019.
Together, the five agencies with all twelve months of 2025 on file reported 2,793 arrests that year. The three of them with both 2025 and 2024 complete reported 2,715 in 2025 against 2,829 in 2024, down 4 percent.
Through August 2026, the four agencies with every month so far on file reported 1,753 arrests, against 1,878 in the same months of 2025.
Booking: Where People Arrested in Williamson County Are Held
A person kept in custody after an arrest in Williamson County is held at the county jail, whichever agency made the arrest, apart from the short stay some city departments' own holding cells allow; a person cited and released at the scene is not booked at all. The jail's record of each person held, with the charges, is a public record of the arrest, and the court file takes over from there.
On an average day in 2023 the jail held about 160 people, up from about 120 in 2019. Its rated capacity in 2023 was 244 beds, and it ran at 66 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
SearchSystems opened and checked the jail page of the Williamson County Sheriff's Office at wcsheriff.com/corrections2.html, phone 618-997-6541, which answered when SearchSystems opened it on October 4, 2026.
A sentence of more than a year is served in state prison; the Illinois Department of Corrections lists its inmates at idoc.illinois.gov/offender/inmatesearch.html.
How to Find Out About an Arrest in Williamson County
An arrest in Williamson County can be traced in two places, depending on where the case stands: the case index of the Circuit Court of Williamson County, which shows whether charges were filed and the next court date (the court records page SearchSystems verified is at williamsoncountyil.gov/departments/circuit-clerk, phone (618) 997-1301); the State's Attorney, which decides whether an arrest becomes a charge (its page is at williamsoncountyil.gov/states-attorney, phone (618) 998-2229).
Illinois is one of the states that lets anyone look up another person's statewide criminal history: conviction information is public under the Uniform Conviction Information Act, through the Illinois State Police. That record shows what agencies reported to the state, which is wider than one county's court index but can lag it.
Getting a Copy of an Arrest Record in Williamson County
The report of an arrest is released by the agency that made it; the jail and the court hold their own records of the same event, but not the report. Under the Illinois Freedom of Information Act the agency must answer within 5 business days, with one 5-day extension, and it may charge copying only after the first 50 pages.
- An arrest by the Williamson County Sheriff's Office: ask its records unit, reached through the office at 618-997-6541.
- An arrest in Marion, Herrin, Carterville, Johnston City, Cambria, Energy or another of the cities listed above: the records unit of the agency that reports for that city; the city guides linked above name each city's records office.
- An arrest by John A. Logan College: the records office of the agency involved.
- A defendant who has been charged gets the report through the case: the State's Attorney, (618) 998-2229, handles discovery for pending cases.
- The court file of a case that was filed: the Circuit Court of Williamson County, through the court records page at williamsoncountyil.gov, phone (618) 997-1301.
- Your own statewide record: a name-based or fingerprint-based request to the Illinois State Police.
Cities in Williamson County: Who Reports the Arrests
The FBI lists a separate arrest reporting agency for seven of the 15 cities in Williamson County: Marion, Herrin, Carterville, Johnston City, Cambria, Energy and Hurst. Crainville, Pittsburg, Creal Springs, Freeman Spur, Bush, Stonefort, Spillertown and Colp have no separate reporting agency in the FBI's list.
Wherever in the county the arrest happens, a person kept in custody goes to the county jail and the case goes to the Circuit Court of Williamson County.
SearchSystems has a guide to the offices of these cities in Williamson County, with the 2024 Census Bureau population; a city with its own arrest records guide opens there:
Frequently Asked Questions
How many arrests are made in Williamson County each year?
Johnston City reported 1,152 arrests to the FBI for 2025, and the five agencies with every month of 2025 on file reported 2,793 between them.
How do I find out if someone is in jail in Williamson County?
Ask the Williamson County Sheriff's Office at 618-997-6541; its jail page SearchSystems verified is at wcsheriff.com/corrections2.html.
Where are people arrested in Williamson County booked?
Those kept in custody go to the county jail, run by the Williamson County Sheriff's Office; a person cited and released at the scene is not booked.
Are arrest records public in Williamson County?
The court files of criminal cases are public, and so is the statewide criminal history kept by the Illinois State Police: conviction information is public under the Uniform Conviction Information Act. The arrest report itself is released by the agency that made the arrest, under the Illinois Freedom of Information Act.
How do I get a copy of an arrest report in Williamson County?
From the agency that made the arrest: the Williamson County Sheriff's Office for its own arrests, or the agency that reports for the city where it happened. Under the Illinois Freedom of Information Act the answer is due within 5 business days, with one 5-day extension.
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.