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 24, 2026 and September 30, 2026.
Knoxville, Iowa, in Marion County, has about 7,400 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Knoxville is held at the county jail, run by the Marion County Sheriff's Office, and the jail's record of each person held is a public record. This guide says where to look for someone in custody, what the jail holds and who books people into it.
This guide covers the search, the jail, who books people, state prison and common questions.
Related guides: Knoxville public records, Marion County inmate search, Knoxville arrest records, Knoxville warrants, Knoxville criminal records, Knoxville court records, Iowa arrest records and Iowa inmate search.
Finding Someone in Custody in Knoxville
The county jail, run by the Marion County Sheriff's Office, holds everyone kept in custody after an arrest in Knoxville, from every agency.
SearchSystems opened and checked the custody page of the Marion County Sheriff's Office at marioncountyiowa.gov/sheriff/whos_in_jail (page title: Who's in Jail? | Sheriff's Office | Marion County, Iowa), which answered when SearchSystems opened it on September 30, 2026.
That page is the place to look for someone booked recently. A person cited and released at the scene, or held only a few hours by a city department, will not be on it.
The Marion County Jail by the Numbers
On an average day in 2019 the jail held about 35 people. Its rated capacity in 2019 was 56 beds, and it ran at 62 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Marion County has about 34,000 residents (2024 Census Bureau estimate), so the jail holds about 10 people for every 10,000 residents.
Who Books People Into the Marion County Jail
The Marion County Sheriff's Office and the agency that reports for Knoxville (filed by the FBI as Knoxville Police Department) make the arrests that end in a booking in and around Knoxville.
The largest arrest counts reported to the FBI were Knoxville's 202 for 2025, the Marion County Sheriff's Office's 185 for 2024 and Pella's 64 for 2025.
Together, the two agencies in Marion County with all twelve months of 2025 on file reported 266 arrests to the FBI that year. Those kept in custody were booked into the county jail; a person cited and released at the scene was not.
The counts, agency by agency and year by year, are in Knoxville arrest records.
From the Jail to State Prison
A sentence of more than a year is served in state prison, not the jail; the Iowa Department of Corrections lists its inmates at doc.iowa.gov/inmate-family-services.
Frequently Asked Questions
How do I find an inmate in Knoxville?
Look on the custody page of the Marion County Sheriff's Office at marioncountyiowa.gov/sheriff/whos_in_jail. It covers people booked into the county jail.
How many people are in the Marion County jail?
About 35 on an average day in 2019, the latest year in the Vera Institute's jail data, against a rated capacity of 56 beds.
Where do people sentenced to prison in Marion County go?
To a facility of the Iowa Department of Corrections; its inmate locator is at doc.iowa.gov/inmate-family-services.
Is this the official Knoxville website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official city, county, court and state offices described above and does not hold records, charge for them or take requests.