Private Investigators in Illinois by City

Licensing

How Illinois Licenses Private Investigators

Illinois regulates private detectives through the Department of Financial and Professional Regulation, known as IDFPR. The governing law is 225 ILCS 447, which IDFPR lists as the Private Detective, Private Alarm, Private Security, and Locksmith Act of 2004. IDFPR issues licenses to individual private detectives, to private detective agencies and to agency branch offices. A person who does investigative work for hire in Illinois is generally expected to hold a license under that Act.

For a client, this means there are two records worth checking. The individual detective should hold an active license in their own name, and the business that signs the contract should hold an active agency license. IDFPR's online License Look-Up shows status and expiration dates for both, so a few minutes of checking can confirm the person and the company match.

Courts

How Illinois Courts Are Organized

Illinois has a single trial court, the circuit court, which hears nearly every kind of case. The state is divided into 25 judicial circuits. Some circuits cover one county, including Cook County, and others group several counties. Within each county the circuit court handles felonies, misdemeanors, traffic, small claims, larger civil suits, divorce, custody, probate and juvenile cases, often in separate divisions. Circuit judges and associate judges both hear cases. Townships and villages do not run their own trial courts for these matters.

Communities

Illinois Communities With a Private Investigator Page

Every Illinois community over 3,000 residents, by population (U.S. Census Bureau, April 1, 2020 estimates base and July 1, 2024 estimates (Vintage 2024)).

Read the full Illinois investigator guide

Neighboring states: Indiana · Iowa · Kentucky · Missouri · Wisconsin