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 September 30, 2026.
Benton County, Washington, has about 218,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Benton County is held at the county jail, run by the Benton 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: Benton County public records, Benton County arrest records, Benton County warrants, Benton County criminal records, Benton County court records, Washington arrest records and Washington inmate search.
Finding Someone in Custody in Benton County
A person kept in custody after an arrest in Benton County is held at the county jail, run by the Benton County Sheriff's Office, whichever agency made the arrest.
SearchSystems opened and checked the custody page of the Benton County Sheriff's Office at bentoncountywa.gov/departments/administration/corrections/daily_jai... (page title: Benton County, WA), phone 509-783-1451, which answered when SearchSystems opened it on September 23, 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 Benton County Jail by the Numbers
On an average day in 2023 the jail held about 420 people, down from about 630 in 2019. Its rated capacity in 2023 was 720 beds, and it ran at 58 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Benton County has about 218,000 residents (2024 Census Bureau estimate), so the jail holds about 19 people for every 10,000 residents.
Who Books People Into the Benton County Jail
The Benton County Sheriff's Office and the agencies that report for Kennewick, Richland, West Richland and Prosser make the arrests that end in a booking in Benton County.
The largest arrest counts reported to the FBI were Kennewick's 2,496 for 2025, Richland's 1,383 for 2025 and the Benton County Sheriff's Office's 301 for 2025.
Together, the five agencies in Benton County with all twelve months of 2025 on file reported 4,460 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 Benton County arrest records.
From the Jail to State Prison
A sentence of more than a year is served in state prison, not the jail; the Washington State Department of Corrections lists its inmates at doc.wa.gov/records/incarcerated-data-search/incarcerated-search.
Frequently Asked Questions
How do I find an inmate in Benton County?
Look on the custody page of the Benton County Sheriff's Office at bentoncountywa.gov, or call 509-783-1451. It covers people booked into the county jail.
How many people are in the Benton County jail?
About 420 on an average day in 2023, the latest year in the Vera Institute's jail data, against a rated capacity of 720 beds.
What is the phone number for the Benton County jail?
509-783-1451, the number on the page of the Benton County Sheriff's Office SearchSystems verified.
Where do people sentenced to prison in Benton County go?
To a facility of the Washington State Department of Corrections; its inmate locator is at doc.wa.gov.
Is this the official Benton 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.