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.
Warren County, Illinois, has about 16,000 residents (2024 Census Bureau estimate), and arrests there are reported to the FBI by the Warren County Sheriff's Office and two city agencies. 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 Warren 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: Warren County public records, Illinois arrest records, Illinois inmate search and Illinois criminal records.
Who Makes Arrests in Warren County
The Warren County Sheriff's Office is the county agency that reports arrests to the FBI for Warren County. It reported 40 arrests for 2025.
The FBI lists two cities in Warren County with a reporting agency of their own, with the Census population and what each reported:
- Monmouth, 8,639 residents: 181 arrests reported for 2025.
- Alexis, 755 residents: 0 arrests reported for 2020.
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 Avon Police Department is listed by the FBI across two counties including Warren County, so its arrests are not broken out for Warren County here.
How Many Arrests Each Agency Reports in Warren County
The FBI publishes every agency's monthly arrest counts 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.
- Monmouth: 181 for 2025, 220 for 2024, 174 for 2023 and 141 for 2022.
- Warren County Sheriff's Office: 40 for 2025, 44 for 2024, 47 for 2023, 53 for 2022, 0 for 2020 and 0 for 2019; 2021 is missing months.
- Alexis: 0 for 2020 and 0 for 2019.
Together, the two agencies with all twelve months of 2025 on file reported 221 arrests that year. The same agencies with both 2025 and 2024 complete reported 221 in 2025 against 264 in 2024, down 16 percent.
Alexis reported only part of 2025 (1 month) and is left out of the totals.
Booking: Where People Arrested in Warren County Are Held
A person kept in custody after an arrest in Warren 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 6 people, down from about 26 in 2019. Its rated capacity in 2019, the last year with a capacity figure, was 42 beds, and it ran at 62 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 Warren County Sheriff's Office at warrencountyil.gov/offices/sheriff (page title: Warren County Sheriff's Office | Warren County IL), phone (309)734-8383, 121 North A Street Monmouth, IL 61462, 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 Warren County
An arrest in Warren County can be traced in two places, depending on where the case stands: the case index of the Circuit Court of Warren County, which shows whether charges were filed and the next court date (the court records page SearchSystems verified is at warrencountyil.gov/offices/circuit-clerk, phone 309-734-5179); the State's Attorney, which decides whether an arrest becomes a charge (its page is at warrencountyil.gov/offices/state-attorney, phone (309) 734-8476).
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 Warren County
An arrest report belongs to the agency whose officer wrote it, and that agency releases it, not the court or the jail. 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 Warren County Sheriff's Office: ask its records unit, reached through the office at (309)734-8383.
- An arrest in Monmouth or Alexis: the records unit of the agency that reports for that city.
- A defendant who has been charged gets the report through the case: the State's Attorney, (309) 734-8476, handles discovery for pending cases.
- The court file of a case that was filed: the Circuit Court of Warren County, through the court records page at warrencountyil.gov/offices/circuit-clerk, phone 309-734-5179.
- Your own statewide record: a name-based or fingerprint-based request to the Illinois State Police.
Cities in Warren County: Who Reports the Arrests
The FBI lists a separate arrest reporting agency for two of the five cities in Warren County: Monmouth and Alexis. Roseville, Kirkwood and Little York 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 Warren County.
Frequently Asked Questions
How many arrests are made in Warren County each year?
Monmouth reported 181 arrests to the FBI for 2025, and the two agencies with every month of 2025 on file reported 221 between them.
How do I find out if someone is in jail in Warren County?
Ask the Warren County Sheriff's Office at (309)734-8383; its jail page SearchSystems verified is at warrencountyil.gov/offices/sheriff.
Where are people arrested in Warren County booked?
Those kept in custody go to the county jail, run by the Warren County Sheriff's Office; a person cited and released at the scene is not booked.
Are arrest records public in Warren 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 Warren County?
From the agency that made the arrest: the Warren 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 Warren 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.