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 2, 2026.
Crystal Lake, Illinois, in McHenry County, has about 42,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Crystal Lake is held at the county jail, run by the McHenry 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: Crystal Lake public records, McHenry County inmate search, Crystal Lake arrest records, Crystal Lake warrants, Crystal Lake criminal records, Crystal Lake court records, Illinois arrest records and Illinois inmate search.
Finding Someone in Custody in Crystal Lake
A person kept in custody after an arrest in Crystal Lake is held at the county jail, run by the McHenry County Sheriff's Office, whichever agency made the arrest.
SearchSystems opened and checked the jail page of the McHenry County Sheriff's Office at mchenrysheriff.org (page title: McHenry County IL Sheriff's Office), which answered when SearchSystems opened it on September 23, 2026.
That page is the office's jail information page rather than a roster.
The McHenry County Jail by the Numbers
On an average day in 2024 the jail held about 380 people, down from about 460 in 2019. Its rated capacity in 2023, the last year with a capacity figure, was 650 beds, and it ran at 29 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
McHenry County has about 316,000 residents (2024 Census Bureau estimate), so the jail holds about 12 people for every 10,000 residents.
Who Books People Into the McHenry County Jail
The McHenry County Sheriff's Office and the agency that reports for Crystal Lake (filed by the FBI as Crystal Lake Police Department) make the arrests that end in a booking in and around Crystal Lake.
The FBI's agency list also places these agencies in McHenry County: McHenry County College (campus police); the McHenry County Conservation District and the Crystal Lake Park District (other agency).
The Lakemoor Police Department, the Fox Lake Police Department and the Barrington Hills Police Department are each listed by the FBI across several counties including McHenry County, so their arrests are not broken out for McHenry County here.
The largest arrest counts reported to the FBI were the McHenry County Sheriff's Office's 820 for 2025, Crystal Lake's 818 for 2025 and Woodstock's 526 for 2025.
Together, the 21 agencies in McHenry County with all twelve months of 2025 on file reported 4,544 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 Crystal Lake arrest records.
From the Jail to State Prison
The jail holds people awaiting trial and people serving short sentences. A person sentenced to prison in McHenry County serves the sentence in a facility of the Illinois Department of Corrections, whose inmate locator is at idoc.illinois.gov/offender/inmatesearch.html.
Frequently Asked Questions
How do I find an inmate in Crystal Lake?
Ask the McHenry County Sheriff's Office; its jail page SearchSystems verified is at mchenrysheriff.org.
How many people are in the McHenry County jail?
About 380 on an average day in 2024, the latest year in the Vera Institute's jail data, against a rated capacity of 650 beds.
Where do people sentenced to prison in McHenry County go?
To a facility of the Illinois Department of Corrections; its inmate locator is at idoc.illinois.gov/offender/inmatesearch.html.
Is this the official Crystal Lake 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.