Williamson County
Its jail, located in Marion, has a capacity of 240.
Williamson County has a population of 67,064 and is classified by the U.S. Department of Agriculture as “Nonmetro - Urban population of 20,000 or more, not adjacent to a metro area”.
Annual inspections
Between 2017 and 2025, the Williamson County jail has failed four of nine Illinois Department of Corrections inspections.
Inspectors cited violations to “Supervision” regulations most often, bringing it up in four of those failed inspections.
| Year | Result | Violations cited |
|---|---|---|
| 2025 | Noncompliant |
|
| 2024 | Noncompliant |
|
| 2023 | Noncompliant |
|
| 2022 | Compliant | — |
| 2021 | Noncompliant |
|
| 2020 | Compliant | — |
| 2019 | Compliant | — |
| 2018 | Compliant | — |
| 2017 | Compliant | — |
Each violation links to the standard it cites in the Illinois County Jail Standards. Years link to the full inspection report for that year on the IDOC website.
Extraordinary or unusual incidents
Williamson County reported 353 extraordinary or unusual incidents at its jail between 2019 and 2025 — 52.6 per 10,000 residents, the 4th highest rate of the 92 Illinois counties with a jail.
Among the 24 non-metro counties with a small urban centre it is 2nd; those counties report a median of 11.8. The median for every county with a jail is 7.
A county reporting less could indicate lower incident rates or lower reporting rates.
Incidents per 10,000 residents
Williamson CountyNon-metro counties with a small urban centre Every other county with a jail
Most frequent categories
- Restraints used262
- OC spray used40
- Assault on staff34
- Taser used31
- Suicide attempt26
A single report can fall into more than one category.
Reported incidents by year
Deaths in custody
Between 2019 and 2025, 1 person died in custody of the Williamson County sheriff. It appears in state oversight data.
Each death in the Williamson County jail
Counted by the state
No deaths in custody were identified at the Williamson County jail.
Illinois Answers withheld the names of some of the deceased at the request of their families.
Data compiled 2026-09-15. Methodology.