Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest and crime counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. Every office link was opened and checked against the office's own site between September 23, 2026 and October 2, 2026.
Lake County, Illinois, has about 719,000 residents (2024 Census Bureau estimate). In Illinois the public criminal record is the court file, kept by the Circuit Clerk; the statewide criminal history kept by the Illinois State Police is open to anyone who asks. This guide says where each record of a criminal case from Lake County is kept and how it is seen.
This guide covers the court file, the statewide record, local arrest records, the crimes behind the records, the prosecutor, sex offender registry, records requests and common questions.
Related guides: Lake County public records, Lake County arrest records, Lake County warrants, Lake County inmate search, Lake County court records, Illinois arrest records and Illinois inmate search.
Criminal Cases in the Circuit Court of Lake County
In Illinois the public criminal record is the court file. Criminal cases from Lake County are heard by the Circuit Court of Lake County, which hears every civil, criminal, family, probate, traffic and juvenile case, and the file of each case is kept by the Circuit Clerk.
For Lake County, SearchSystems opened and checked the court records page for the county at ilsos.gov/departments/archives/databases/lake.html (page title: Lake County Circuit Court Case Files Index (1840-1898)), phone 815-753-1807, which answered when SearchSystems opened it on September 23, 2026.
Illinois has no single public index of every trial court case; each court's records are looked up through that court.
The Illinois Criminal History and Your Own Copy
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. The result is the repository record, what agencies reported to the state, which is wider than one county's court index but can lag it.
To see your own record, the route is a name-based or fingerprint-based request to the Illinois State Police. The state page SearchSystems verified for it is at isp.illinois.gov/BureauOfIdentification/MyRecord.
Arrest Records Kept Locally in Lake County
The Lake County Sheriff's Office and the agencies that report for Waukegan, Buffalo Grove, Mundelein, Highland Park, North Chicago, Gurnee and 27 more cities keep the arrest records in Lake County: the report and the booking record of each arrest stay with the agency that made it, separate from the court file and from the state repository.
The FBI's agency list also places one campus police department and three other agencies in Lake County (the arrest records guide names each one); each keeps the records of its own arrests.
The Barrington Police Department, the Island Lake Police Department, the Fox River Grove Police Department and one more are each listed by the FBI across several counties including Lake County, so their arrests are not broken out for Lake County here.
Together, the 31 agencies in Lake County with all twelve months of 2025 on file reported 7,816 arrests to the FBI that year; how each case ended is in the court file, not in the arresting agency's.
The agencies and their counts, year by year, are in Lake County arrest records.
The Crimes Behind the Records: Lake County in 2025
The 32 agencies in Lake County with all twelve months of 2025 on file reported 840 violent and 5,223 property crimes to the FBI that year; the 30 of them with both 2025 and 2024 complete reported 5,414 crimes in 2025 against 6,348 in 2024. Each reported crime is a report on file with the agency that took it, and each arrest that follows is the start of a criminal record.
The full crime section, agency by agency, is on the Lake County public records guide.
The State's Attorney for Lake County
Charges in Lake County are filed by the State's Attorney, which reviews the arrests of every agency in the county and brings the cases in the Circuit Court of Lake County.
The office's page SearchSystems verified is at lakecountyil.gov/513/States-Attorneys-Office (page title: State's Attorney's Office | Lake County, IL), a site that blocks automated checks (HTTP 429), so open it in a browser.
The Sex Offender Registry for Lake County
Registered sex offenders living in Lake County are listed on the Illinois Sex Offender Registry, run by the Illinois State Police at illinois.gov. The registry is public and can be searched online.
Registration itself is done in person with the local agency where the registrant lives: the sheriff's office, or the city police in a city with its own department.
Asking an Agency in Lake County for a Record
An arrest report, a booking record or a local criminal history letter comes from the agency that holds it, not from the court.
Under the Illinois Freedom of Information Act a county office must answer a request within 5 business days, with one 5-day extension, and it may charge copying only after the first 50 pages.
Frequently Asked Questions
Are criminal records public in Lake 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.
Can I search Lake County criminal cases online?
The court records page SearchSystems verified for the county is at ilsos.gov (page title: Lake County Circuit Court Case Files Index (1840-1898)).
How do I get my own Illinois criminal history?
Through a name-based or fingerprint-based request to the Illinois State Police.
Who prosecutes crimes in Lake County?
The State's Attorney, which files its cases in the Circuit Court of Lake County.
Is this the official Lake 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.