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.
McHenry County, Illinois, has about 316,000 residents (2024 Census Bureau estimate), and arrests there are reported to the FBI by the McHenry County Sheriff's Office, 23 city agencies and three campus, state or other 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 McHenry 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: McHenry County public records, Illinois arrest records, Illinois inmate search and Illinois criminal records.
Who Makes Arrests in McHenry County
The McHenry County Sheriff's Office is the county agency that reports arrests to the FBI for McHenry County. It reported 820 arrests for 2025.
Arrests inside 23 of the county's cities are reported to the FBI by an agency of the city's own, listed here with the Census population and what each reported, the largest twelve first; the rest are named in the cities section below:
- Crystal Lake, 41,513 residents: 818 arrests reported for 2025.
- Algonquin, 30,539 residents: 323 arrests reported for 2025.
- McHenry, 28,825 residents: 424 arrests reported for 2025.
- Lake in the Hills, 28,706 residents: 313 arrests reported for 2025.
- Huntley, 28,495 residents: 161 arrests reported for 2025.
- Woodstock, 25,892 residents: 526 arrests reported for 2025.
- Cary, 18,031 residents: 275 arrests reported for 2025.
- Harvard, 9,408 residents: 212 arrests reported for 2025.
- Island Lake, 8,066 residents: 155 arrests reported for 2025.
- Marengo, 7,699 residents: 158 arrests reported for 2025.
- Johnsburg, 6,428 residents: 69 arrests reported for 2022.
- Spring Grove, 5,554 residents: 67 arrests reported for 2025.
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 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 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).
How Many Arrests Each Agency Reports in McHenry County
Each agency reports its arrests to the FBI by month, and the FBI publishes them 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.
- McHenry County Sheriff's Office: 820 for 2025, 940 for 2024 and 764 for 2023.
- Crystal Lake: 818 for 2025, 920 for 2024 and 692 for 2023.
- Woodstock: 526 for 2025, 453 for 2024, 411 for 2023 and 422 for 2022.
- McHenry: 424 for 2025, 542 for 2024, 448 for 2023, 410 for 2022 and 358 for 2021.
- Algonquin: 323 for 2025, 324 for 2024, 339 for 2023, 297 for 2022 and 332 for 2021.
- Lake in the Hills: 313 for 2025, 326 for 2024, 207 for 2023, 185 for 2022 and 171 for 2021.
- Cary: 275 for 2025, 146 for 2024 and 172 for 2023.
- Harvard: 212 for 2025, 169 for 2024, 283 for 2023, 247 for 2022 and 169 for 2021.
- Huntley: 161 for 2025, 223 for 2024, 176 for 2023 and 234 for 2022.
- Marengo: 158 for 2025, 162 for 2024 and 111 for 2023.
- Island Lake: 155 for 2025 and 186 for 2024.
- Richmond: 89 for 2025 and 117 for 2023; 2024 is missing months.
Together, the 21 agencies with all twelve months of 2025 on file reported 4,544 arrests that year. The 20 of them with both 2025 and 2024 complete reported 4,455 in 2025 against 4,713 in 2024, down 5.5 percent.
Through July 2026, the 17 agencies with every month so far on file reported 2,548 arrests, against 2,512 in the same months of 2025.
Booking: Where People Arrested in McHenry County Are Held
The county jail is where a person arrested in McHenry County and kept in custody ends up, whichever agency made the arrest, though a city department may hold someone in its own cells first and a person cited and released at the scene is never booked. The jail's record of each person held, with the charges, is a public record of the arrest, and once the person is released or sentenced the record continues in the court file.
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.
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.
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 McHenry County
For McHenry County the place to look is the State's Attorney, which decides whether an arrest becomes a charge (its page is at mchenrycountyil.gov/departments/state-s-attorney-s-office, phone (815) 334-4159).
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 McHenry County
The report of an arrest is released by the agency that made it; the jail and the court hold their own records of the same event, but not the report. 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 McHenry County Sheriff's Office: ask its records unit.
- An arrest in Crystal Lake, Algonquin, McHenry, Lake in the Hills, Huntley, Woodstock or another of the cities listed above: the records unit of the agency that reports for that city; the city guides linked above name each city's records office.
- An arrest by McHenry County College, the McHenry County Conservation District or the Crystal Lake Park District: the records office of the agency involved.
- A defendant who has been charged gets the report through the case: the State's Attorney, (815) 334-4159, handles discovery for pending cases.
- Your own statewide record: a name-based or fingerprint-based request to the Illinois State Police.
Cities in McHenry County: Who Reports the Arrests
The FBI lists a separate arrest reporting agency for 23 of the 27 cities in McHenry County: the twelve named above and Wonder Lake, Fox River Grove, Lakewood, Richmond, Oakwood Hills, Prairie Grove, Hebron, Bull Valley, McCullom Lake, Union and Holiday Hills. Port Barrington, Ringwood, Trout Valley and Greenwood 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 McHenry County.
SearchSystems has a guide to the offices of these cities in McHenry County, with the 2024 Census Bureau population; a city with its own arrest records guide opens there:
- Crystal Lake (41,513)
- Huntley (28,495)
- Marengo (7,699)
Frequently Asked Questions
How many arrests are made in McHenry County each year?
The McHenry County Sheriff's Office reported 820 arrests to the FBI for 2025, and the 21 agencies with every month of 2025 on file reported 4,544 between them.
How do I find out if someone is in jail in McHenry County?
Ask the McHenry County Sheriff's Office; its jail page SearchSystems verified is at mchenrysheriff.org.
Where are people arrested in McHenry County booked?
Those kept in custody go to the county jail, run by the McHenry County Sheriff's Office; a person cited and released at the scene is not booked.
Are arrest records public in McHenry 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 McHenry County?
From the agency that made the arrest: the McHenry 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 McHenry 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.