Inside Illinois Jails

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Boone County


Its jail, located in Belvidere, has a capacity of 128.

Boone County has a population of 53,313 and is classified by the U.S. Department of Agriculture as “Metro - Counties in metro areas of 250,000 to 1 million population”.

2inspections failed since 2017
46incidents reported 2019–2025
0deaths in custody since 2019

Annual inspections

Between 2017 and 2025, the Boone County jail has failed two of nine Illinois Department of Corrections inspections.

YearResultViolations cited
2025Compliant
2024Compliant
2023Compliant
2022Noncompliant
2021Compliant
2020Noncompliant
2019Compliant
2018Compliant
2017Compliant

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

Boone County reported 46 extraordinary or unusual incidents at its jail between 2019 and 2025 — 8.6 per 10,000 residents, the 40th highest rate of the 92 Illinois counties with a jail.

Among the 36 metropolitan counties it is 18th; those counties report a median of 8.3. 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

Boone CountyMetropolitan counties Every other county with a jail

Boone 8.6020406080100
Each dot is one of the 92 Illinois counties with a jail, placed by its rate.

Most frequent categories

A single report can fall into more than one category.

Reported incidents by year

  • 20193
  • 20205
  • 20214
  • 202210
  • 20231
  • 202419
  • 20254

Deaths in custody

No deaths in custody were identified at the Boone County jail.

Data compiled 2026-09-15. Methodology.