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 on September 23, 2026.
Jefferson County, Colorado, has about 579,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Jefferson County is held at the county jail, run by the Jefferson 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: Jefferson County public records, Jefferson County arrest records, Jefferson County warrants, Jefferson County criminal records, Jefferson County court records, Colorado arrest records and Colorado inmate search.
Finding Someone in Custody in Jefferson County
The county jail, run by the Jefferson County Sheriff's Office, holds everyone kept in custody after an arrest in Jefferson County, from every agency.
SearchSystems opened and checked the custody page of the Jefferson County Sheriff's Office at jeffcosheriffco.gov/jail/inmate-lookup (page title: Inmate Lookup | Jeffco Sheriff), phone (303) 271-5444, which answered when SearchSystems opened it on September 23, 2026.
Someone booked recently shows on that page; someone cited and released at the scene, or held a few hours at a city station, does not.
The Jefferson County Jail by the Numbers
On an average day in 2025 the jail held about 810 people, down from about 1,220 in 2019. Its rated capacity in 2025 was 1,638 beds, and it ran at 50 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Jefferson County has about 579,000 residents (2024 Census Bureau estimate), so the jail holds about 14 people for every 10,000 residents.
Who Books People Into the Jefferson County Jail
The Jefferson County Sheriff's Office and the agencies that report for Lakewood, Arvada, Wheat Ridge, Golden, Edgewater, Mountain View and one more cities make the arrests that end in a booking in Jefferson County.
The FBI's agency list also places these agencies in Jefferson County: the Division of Gaming Criminal Enforcement and Investigations Section, Golden (state agency); Colorado School of Mines and Red Rocks Community College (campus police).
The Westminster Police Department, the Bow Mar Police Department and the Littleton Police Department are each listed by the FBI across several counties including Jefferson County, so their arrests are not broken out for Jefferson County here.
The largest arrest counts reported to the FBI were Lakewood's 8,420 for 2025, Arvada's 4,837 for 2025 and the Jefferson County Sheriff's Office's 1,714 for 2025.
Together, the eight agencies in Jefferson County with all twelve months of 2025 on file reported 17,570 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 Jefferson 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 Colorado Department of Corrections lists its inmates at cdoc.colorado.gov.
Frequently Asked Questions
How do I find an inmate in Jefferson County?
Look on the custody page of the Jefferson County Sheriff's Office at jeffcosheriffco.gov/jail/inmate-lookup, or call (303) 271-5444. It covers people booked into the county jail.
How many people are in the Jefferson County jail?
About 810 on an average day in 2025, the latest year in the Vera Institute's jail data, against a rated capacity of 1,638 beds.
What is the phone number for the Jefferson County jail?
(303) 271-5444, the number on the page of the Jefferson County Sheriff's Office SearchSystems verified.
Where do people sentenced to prison in Jefferson County go?
To a facility of the Colorado Department of Corrections; its inmate locator is at cdoc.colorado.gov.
Is this the official Jefferson 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.