Cook County

5,194,625 people, served by 178 police agencies that report to the FBI. Below: how a case moves here, from arrest to court.

How a case moves here

Cook County follows Illinois law on arrests, release, and courts. These rules are the same in every county in the state; the full set covers prosecutors, defense, and jails too.

Who decides release first: Illinois has no money bail. Police may release a person charged with an offense for which release can't be denied, without a judge. Anyone charged with an offense for which the state can seek detention goes before a circuit or associate judge.
725 ILCS 5/109-1
Time to see a judge: A person arrested and not released must be taken before a judge without unnecessary delay and within 48 hours, and a charge must be filed.
725 ILCS 5/109-1(a)
Money bail: Illinois abolished money bail under the Pretrial Fairness Act, which took effect September 18, 2023. Judges release people on conditions or, after a hearing on a state petition, order them detained.
725 ILCS 5/110-1.5
Courts: Illinois has one trial court, the circuit court, which hears every felony and misdemeanor. There are no city, county, or justice courts.
Ill. Const. art. VI, secs. 1, 9
Judges and magistrates: Circuit judges are nominated in party primaries or by petition and elected to six-year terms, then run in retention elections to stay. Circuit judges appoint associate judges to four-year terms. Every judge must be a licensed Illinois lawyer.
Ill. Const. art. VI, secs. 8, 10, 11, 12

Read from the statutes and court rules cited, 2026-09-30. 725 ILCS 5/110-1.5 states January 1, 2023, but the Illinois Supreme Court stayed the law until September 18, 2023 (Rowe v. Raoul); the stay is from general knowledge, not a source read here. Retention needs three-fifths of votes cast; not re-read. How small counties without a public defender office provide lawyers was not confirmed county by county.

What this county does differently

Pretrial practice: The Office of Statewide Pretrial Services lists this county as one it does not serve, and Advancing Pretrial lists it as a Public Safety Assessment site since 2015.
Advancing Pretrial Policy and Research, PSA sites list (page modified 2026-06-03)Illinois Office of Statewide Pretrial Services, Pretrial Services Directory (read 2026-09-30)

Police agencies

Agencies: FBI NIBRS master file 2025 batch headers; names from the FBI agency list, pulled 2026-09-29. An agency that serves several counties appears on each. Population served is the FBI's figure.

Crime and arrests

No figures yet

Reported offenses and arrests for Cook County, counted by the agencies that serve it, appear here once the county series is published. NIBRS reporting here started as early as July 2020.