Warren County
Its jail, located in Monmouth, has a capacity of 22.
Warren County has a population of 16,217 and is classified by the U.S. Department of Agriculture as “Nonmetro - Urban population of 5,000 to 20,000, adjacent to a metro area”.
Annual inspections
Between 2017 and 2025, the Warren County jail has failed seven of nine Illinois Department of Corrections inspections.
Inspectors cited violations to “Security” regulations most often, bringing it up in six of those failed inspections.
| Year | Result | Violations cited |
|---|---|---|
| 2025 | Noncompliant |
|
| 2024 | Noncompliant |
|
| 2023 | Noncompliant |
|
| 2022 | Noncompliant |
|
| 2021 | Compliant | — |
| 2020 | Noncompliant |
|
| 2019 | Noncompliant |
|
| 2018 | Noncompliant |
|
| 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
Warren County reported 10 extraordinary or unusual incidents at its jail between 2019 and 2025 — 6.2 per 10,000 residents, the 52nd highest rate of the 92 Illinois counties with a jail.
Among the 24 non-metro counties with a small urban centre it is 19th; 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
Warren CountyNon-metro counties with a small urban centre Every other county with a jail
Most frequent categories
- Restraints used7
- Serious injury3
- Assault on staff3
- Suicide attempt2
- Taser used1
A single report can fall into more than one category.
Reported incidents by year
Deaths in custody
No deaths in custody were identified at the Warren County jail.
Illinois Answers withheld the names of some of the deceased at the request of their families.
Data compiled 2026-09-15. Methodology.